
USCA1 Opinion

	




                            UNITED STATES COURT OF APPEALS                                FOR THE FIRST CIRCUIT                              _________________________          Nos. 92-1362               92-1574                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                   DAVID SEPULVEDA,                                Defendant, Appellant.                              _________________________          No. 92-1364                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                   EDGAR SEPULVEDA,                                Defendant, Appellant.                              _________________________          No. 92-1366                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                EDWARD W. WELCH, JR.,                                Defendant, Appellant.                              _________________________          No. 92-1367                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                   ARLINE S. WELCH,                                Defendant, Appellant.                              _________________________          No. 92-1369                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                   KEVIN CULLINANE,                                Defendant, Appellant.                              _________________________          No. 92-1371                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                  CHERYL T. JOHNSON,                                Defendant, Appellant.                              _________________________          No. 92-1373                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                  RICHARD F. LABRIE,                                Defendant, Appellant.                              _________________________          No. 92-1374                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                      TONY ROOD,                                Defendant, Appellant.                              _________________________          No. 92-1375                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                 WILLIAM D. WALLACE,                                Defendant, Appellant.                              _________________________          Nos. 92-1573               92-1629                              UNITED STATES OF AMERICA,                                      Appellee,                                          v.                                 ERNEST F. LANGLOIS,                                Defendant, Appellant.                              _________________________                    APPEALS FROM THE UNITED STATES DISTRICT COURT                          FOR THE DISTRICT OF NEW HAMPSHIRE                      [Hon. Shane Devine, U. S. District Judge]                                          ____________________                              _________________________                                        Before                        Selya, Cyr and Boudin, Circuit Judges.                                               ______________                              _________________________               David  H. Bownes,  with whom  David H.  Bownes, P.C.  was on               ________________              ______________________          brief, for defendant David Sepulveda.               Julia M. Nye, with whom McKean, Mattson and Latici, P.A. was               ____________            ________________________________          on brief, for defendant Edgar Sepulveda.               Stephen A. Cherry,  with whom Wright & Cherry  was on brief,               _________________             _______________          for defendant Edward W. Welch, Jr.               Kevin M. Fitzgerald, with whom Peabody & Brown was on brief,               ___________________            _______________          for defendant Arline S. Welch.               Michael J. Ryan, with whom King  and Ryan was on brief,  for               _______________            ______________          defendant Kevin Cullinane.               Robert P. Woodward for defendant Cheryl T. Johnson.               __________________               Mark H. Campbell for defendant Richard Labrie.               ________________               Paul J. Garrity on brief for defendant Tony Rood.               _______________               Matthew J.  Lahey, with  whom Murphy,  McLaughlin, Hemeon  &               _________________             ______________________________          Lahey, P.A. was on brief, for defendant William D. Wallace.          ___________               Julie  L. Lesher,  with whom  Murphy,  McLaughlin, Hemeon  &               ________________              ______________________________          Lahey, P.A. was on brief, for defendant Ernest F. Langlois.          ___________               John  P. Rab for defendant Christopher Driesse (appellant in               ____________          consolidated appeal).               Paul J.  Haley, with  whom Scott L.  Hood was on  brief, for               ______________             ______________          defendant Shane Welch (appellant in consolidated appeal).               Kevin M. Fitzgerald, Kevin M. Leach, McLane, Graf, Raulerson               ___________________  ______________  _______________________          &  Middleton, Peabody  & Brown  and  David H.  Bownes on  omnibus          ____________  ________________       ________________          briefs for all appellants.               Terry L.  Ollila, Special Assistant United  States Attorney,               ________________          with whom Peter E. Papps,  United States Attorney, and Jeffrey S.                    ______________                               __________          Cahill,  Special Assistant United States Attorney, were on brief,          ______          for appellee.                              _________________________                                  December 20, 1993                              _________________________                    SELYA,  Circuit Judge.   These appeals, arising  out of                    SELYA,  Circuit Judge.                            _____________          the  drug-trafficking  convictions  of   a  dozen  New  Hampshire          residents, suggest  that while  two New  Hampshiremen might  once          have been a match for Satan, see Stephen Vincent Benet, The Devil                                       ___                        _________          and Daniel Webster (1937), times have changed.  The tale follows.          __________________          I.  BACKGROUND          I.  BACKGROUND                    During a  two-month trial  in the  district court,  the          government mined a golconda of  evidence.  Because it would serve          no useful purpose to recount the occasionally ponderous record in          book and  verse, we  offer instead an  overview of  the evidence,          taken in the light most compatible with the guilty verdicts.  See                                                                        ___          United States  v. Ortiz, 966 F.2d 707, 711 (1st Cir. 1992), cert.          _____________     _____                                     _____          denied, 113  S. Ct. 1005 (1993).  Further  facts will be added as          ______          we discuss specific issues.                    For  almost  six  years, David  Sepulveda  conducted an          increasingly sophisticated  cocaine distribution business  in and          around Manchester, New Hampshire.  Initially, Sepulveda purchased          cocaine from  a vendor in Nashua, New  Hampshire, and transported          it  to Manchester  himself.   Over time,  Sepulveda expanded  his          operation, increasing the  volume of cocaine and  engaging others          to handle tasks such as pickup, delivery, and street-level sales.                    As his  enterprise grew more ambitious, Sepulveda began          purchasing  cocaine from  a  source  in Lawrence,  Massachusetts.          Faced with the  need to retain  control while insulating  himself          from  the prying eyes  of law enforcement  personnel, Sepulveda's          journeys to Lawrence became an elaborate ritual in which he would                                          4          scrupulously avoid carrying  drugs or travelling in  the same car          with the cocaine that he purchased.  On these provisioning trips,          Sepulveda was usually  accompanied by his  brother, Edgar, and  a          "runner," that is, an individual who would actually transport the          cocaine  from  Lawrence  to  Manchester.1    Frequently,  one  of          Sepulveda's  distributors  or a  user  in a  particular  hurry to          obtain fresh supplies would join the troupe.                    Once the cocaine arrived  in Manchester, Sepulveda  and          his  associates  packaged  it   in  street-level  quantities  and          distributed it to a series of individuals for resale and personal          use.   The buyers included,  among others,  defendants Edward  W.          Welch,  Jr., Arline  S.  Welch,  Shane  Welch,  Kevin  Cullinane,          Christopher Driesse, Cheryl  T. Johnson, Richard E.  Labrie, Tony          Rood, and William D. Wallace.  David Sepulveda made a practice of          directing  persons who inquired about purchasing small amounts of          cocaine to these same individuals.                    Eventually, David Sepulveda's reach exceeded his grasp.          A federal  grand jury indicted  him, along with others,  for drug          trafficking;  and, after  trial, a  petit  jury convicted  twelve          persons,  viz.,  the  Sepulveda  brothers,  the  three   Welches,                    ____          Cullinane, Driesse, Johnson, Labrie, Rood, Wallace, and Langlois,          on a charge of conspiracy to possess and distribute cocaine.  See                                                                        ___          21 U.S.C.    846 (1988).  The jury also convicted David Sepulveda          on a charge of engaging in a continuing criminal enterprise.  See                                                                        ___                                        ____________________               1At  various times,  defendants  Tony  Rood  and  Ernest  F.          Langlois  worked as  runners.   At  other  times, Norberto  Perez          played this role.                                          5          21 U.S.C.   848 (1988).  Twenty-six appeals ensued.                    It  is  no  exaggeration to  say  that  the defendants,          represented by able  counsel, managed to cultivate a profusion of          variegated  grounds for appeal  from the  peat of  the protracted          trial.    Because  of  the  sheer  bulk  and  complexity  of  the          proceedings, we issued  a special briefing  order and then  heard          oral argument on all twenty-six  appeals.  We decide today twelve          appeals   taken    by   ten   defendants    (collectively,   "the          appellants").2  After sifting what  grains we can locate from the          considerable chaff,  we conclude  that the  appellants enjoyed  a          fair, substantially error-free trial, and  that their convictions          must  stand.   In two  instances, however,  we  vacate particular          sentences and remand for further proceedings.          II.  SUFFICIENCY OF THE EVIDENCE          II.  SUFFICIENCY OF THE EVIDENCE                    Four   appellants   claim   that    the   evidence   is          insufficient,  as a matter of law, to support their convictions.3          Because insufficiency claims are commonplace in criminal appeals,          the   standard  of  appellate  oversight  lends  itself  to  rote                                        ____________________               2The  appeals taken  by defendants  Christopher Driesse  and          Shane Welch following the trial present certain unique issues and          those two  appeals will  be resolved in  a separate opinion.   In          addition, after the  original round of appeals had been docketed,          all twelve  defendants moved to  vacate judgment on the  basis of          newly discovered evidence.   The court below denied  relief and a          fresh  battery of  appeals ensued.    Those twelve  late-blooming          appeals were argued in  tandem with the fourteen earlier  appeals          and will be disposed of in a third opinion.               3We  do not  include  under  this  rubric  appellants  Edgar          Sepulveda and Tony  Rood, both of whom argue  that the government          failed to present sufficient evidence to show their participation          in  the single  "master conspiracy"  charged  in the  indictment.          Instead, we treat with those claims in Part IX, infra.                                                          _____                                          6          recitation.  Following  a guilty verdict, a  reviewing court must          scrutinize  the  record,  eschewing  credibility  judgments   and          drawing all  reasonable inferences  in favor  of the verdict,  to          ascertain if a rational jury could have found that the government          proved each element of the crime beyond  a reasonable doubt.  See                                                                        ___          United States  v. Echeverri, 982  F.2d 675, 677 (1st  Cir. 1993);          _____________     _________          Ortiz, 966 F.2d at 711; United States v. David, 940 F.2d 722, 730          _____                   _____________    _____          (1st Cir. 1991) (collecting cases), cert. denied, 112 S. Ct. 2301                                              _____ ______          (1992).   To sustain  a conviction, the  court need  not conclude          that only a guilty verdict  appropriately could be reached; it is          enough  that  the finding  of  guilt  draws  its essence  from  a          plausible reading of the record.  See Echeverri, 982 F.2d at 677;                                            ___ _________          Ortiz, 966 F.2d at 711.          _____                    Here, the challenged convictions center around a charge          of conspiracy to possess and distribute cocaine.  To prove a drug          conspiracy  charge  under 21  U.S.C.     846,  the government  is          obliged  to show  beyond  a reasonable  doubt  that a  conspiracy          existed and that a particular defendant agreed to participate  in          it, intending to commit the underlying substantive offense (here,          possession  of cocaine  with  intent to  distribute, 21  U.S.C.            841(a)(1)).    See David,  940  F.2d  at  735; United  States  v.                         ___ _____                       ______________          Sanchez, 917 F.2d 607, 610 (1st Cir. 1990), cert.  denied, 111 S.          _______                                     _____  ______          Ct. 1625 (1991); United States v. Rivera-Santiago, 872 F.2d 1073,                           _____________    _______________          1079 (1st Cir.), cert. denied, 492 U.S. 910 (1989).  There are no                           _____ ______          particular formalities that  attend this showing:   the agreement          may  be  express  or  tacit  and  may  be  proved  by  direct  or                                          7          circumstantial evidence.  See Echeverri, 982 F.2d at 679; Rivera-                                    ___ _________                   _______          Santiago, 872 F.2d at 1079.   Moreover, in a criminal conspiracy,          ________          culpability may be constant  though responsibilities are divided;          the government does not need to show as a precursor to  a finding          of guilt that a given defendant  took part in all aspects of  the          conspiracy.   See United States  v. Benevides, 985 F.2d  629, 633                        ___ _____________     _________          (1st Cir. 1993); United  States v. Cruz, 981  F.2d 613, 617  (1st                           ______________    ____          Cir. 1992).  Using these guideposts, we find  that the quantum of          evidence presented against each of the four challengers suffices.                                  A.  Arline Welch.                                  A.  Arline Welch.                                      ____________                    Four  witnesses  provided  the  bulk  of  the  evidence          regarding Arline Welch's  role in the  conspiracy.  Kurt  Coriaty          testified that he had purchased cocaine from her both in her home          and  in his,  particularly after  her husband, Edward  Welch, was          imprisoned.  Coriaty's partner, Kenneth Milne, stated that Arline          Welch  gave  him cocaine  at  her home  and was  present  when he          purchased  cocaine  from  Edward Welch  at  the  Welch residence.          While mere presence is not sufficient to ground criminal charges,          a defendant's presence at the point of a drug sale, taken  in the          light of attendant circumstances, can constitute strong  evidence          of complicity.  See Ortiz, 966 F.2d at 711-12.                          ___ _____                    The  jury also heard Norberto Perez explain that Arline          Welch  accompanied David Sepulveda on three buying expeditions to          Lawrence,  Massachusetts.   Perez testified  that, in  expressing          anxiety, she made  manifest her awareness of the  trips' purpose,          voicing statements like:  "Let's hurry up and get this cocaine so                                          8          we can get out of  here."  Furthermore, Randall Vetrone testified          that  Arline Welch  was present  in  Edgar Sepulveda's  apartment          while  the   Sepulveda  brothers   packaged  and   sold  cocaine.          Appellant's consensual presence in a  private home, not her  own,          while large quantities of  drugs were being packaged for  resale,          possessed evidentiary significance.  From this fact, coupled with          other  contextual detail  (much  of  it  inculpatory),  the  jury          reasonably could have inferred that she was a member of the ring.          See Ortiz,  966 F.2d at  712 (pointing out that  criminals rarely          ___ _____          seek  to expose their felonious activities to innocent outsiders,          where such  exposure could easily  be avoided); United  States v.                                                          ______________          Batista-Polanco,  927 F.2d  14, 18-19  (1st Cir.  1991)  (to like          _______________          effect).                    Keeping in mind the maxim that "criminal juries are not          expected to  ignore what  is perfectly  obvious," Echeverri,  982                                                            _________          F.2d  at 679,  the  testimony  of these  four  witnesses and  the          reasonable  inferences to be drawn therefrom formed a serviceable          predicate  upon  which to  rest  a conviction  for  conspiracy to          distribute cocaine.4  Accordingly, the district court did not err          in denying Arline Welch's motion for judgment of acquittal.                                 B.  Kevin Cullinane.                                 B.  Kevin Cullinane.                                     _______________                    Daniel  Santos, a quondam partner of Cullinane's in the                                        ____________________               4We give short shrift to Welch's argument, echoed at various          times by other appellants, that, because some of the government's          witnesses anticipated receiving reduced sentences in exchange for          cooperation,  their  testimony should  be regarded  as inherently          unreliable.   When an appellate  court reviews the sufficiency of          the  evidence, it must  resolve routine credibility  questions in          favor of the verdict.  See David, 940 F.2d at 730.                                 ___ _____                                          9          drug distribution  trade, testified that Cullinane introduced him          to  David  Sepulveda  and  that  Sepulveda  eventually  became  a          principal   supplier   of   cocaine   to   the   Cullinane-Santos          partnership.  Santos  also testified  that Cullinane  accompanied          Sepulveda on provisioning trips, returning to  Santos's apartment          with fresh supplies of contraband.  The ubiquitous Norberto Perez          corroborated  this relationship, testifying that he had travelled          to  Lawrence  on  at  least  five occasions  in  the  company  of          Cullinane  and the  Sepulveda  siblings  in  order  to  replenish          cocaine stores.   Perez also  recreated a conversation  that took          place  between  Cullinane and  Sepulveda  involving  the former's          indebtedness to the latter for transactions in cocaine.                    The government adduced abundant evidence that Cullinane          distributed much of the contraband he acquired.  Perez and Santos          both described Cullinane's  activities as  a vendor.   John  Rice          testified   that  Cullinane   delivered   cocaine  to   defendant          Christopher Driesse, and that Driesse,  in turn, would resell the          drugs.  Santos confirmed that Cullinane procured these drugs from          David  Sepulveda and that Sepulveda extended credit to Cullinane.          Another  witness, David Chase, acknowledged that he had purchased          up to eight kilograms of cocaine from Cullinane before concluding          that,  aphorisms  about   honor  among  thieves  notwithstanding,          Cullinane could not be trusted.5                    In  view of  this  plenitudinous  testimony, the  court                                        ____________________               5When Chase and Cullinane fell  out, Chase took his business          directly to David Sepulveda.                                          10          below appropriately derailed Cullinane's quest for acquittal as a          matter of law.                                 C.  Ernest Langlois.                                 C.  Ernest Langlois.                                     _______________                    David  Sepulveda hired  Langlois  to  be  both  a  drug          courier  and  a torpedo.   Langlois's  resounding success  in the          latter  role    intimidating Sepulveda's debtors  and, sometimes,          his  associates    produced  a  suffusion  of  testimony  limning          Langlois's role in  the organization.   For instance, David  Hill          described four occasions on which Langlois used force, or threats          of  force,  to  collect  debts  owed to  Sepulveda.    Two  other          witnesses testified that Sepulveda boasted of  employing Langlois          as a strongarm to collect  drug debts.  Another witness overheard          Langlois  crowing about  the nature  of his  employment.   And no          fewer  than  six  witnesses  relayed  information  from  which  a          rational jury  could infer  that Langlois  "rode shotgun"  during          drug-buying expeditions.                    As  this  partial   summary  indicates,  the   evidence          accumulated  against Langlois rose well above the level necessary          to sustain the jury's verdict.                                 D.  Cheryl Johnson.                                 D.  Cheryl Johnson.                                     ______________                    Two witnesses, Santos and  Kathy Malone (an  undercover          police  officer), testified  that David  Sepulveda  sent them  to          Cheryl Johnson when they wanted to buy cocaine.  Santos said that          he  purchased cocaine from  Johnson on approximately  one hundred          occasions, during which transactions Johnson offhandedly revealed                                          11          the full extent of her  copious cocaine inventory.  Malone stated          that  she purchased  cocaine from  Johnson  on three  occasions.6          Perez  testified that  he,  too,  bought  cocaine  from  Johnson,          delivered  cocaine  to   Johnson  at   Sepulveda's  behest,   and          accompanied her on at least one buying trip to Lawrence.                    Although Johnson argues  vehemently that the  witnesses          against  her were inherently  unreliable, courts must  leave such          credibility determinations in the jury's  domain.  See David, 940                                                             ___ _____          F.2d  at  730.   Here,  the jury  was  at liberty  to  credit the          testimony, and it,  in turn, supplied all  the elements necessary          to convict.          III.  SEQUESTRATION          III.  SEQUESTRATION                    Appellants claim  that, shortly after  sentencing, they          learned for the  first time that the government  housed three key          witnesses (Perez, Milne, and Coriaty) in the same cell throughout          the trial.  Appellants moved for a  new trial,7 alleging that the          housing arrangements violated a sequestration order issued by the          district  court.  The  government not only  contested appellants'          conclusion but also contested the premise on which the conclusion                                        ____________________               6Both  Santos and  Malone also  testified  that they  bought          cocaine from defendant Richard Labrie at Johnson's abode.               7These motions are separate from,  and much earlier in  time          than,  the  motions  to  which  we  alluded  in  note  2,  supra.                                                                     _____          Nonetheless,  these motions, like the later motions, invoked Fed.          R. Crim.  P. 33. We  grant appellants a  considerable indulgence,          assuming arguendo that the  information concerning the witnesses'                   ________          living arrangements was  not discoverable before or  during trial          with the exercise of due diligence.  See United States  v. Slade,                                               ___ _____________     _____          980  F.2d 27, 29 (1st  Cir. 1992) (articulating standard); United                                                                     ______          States v. Natanel,  938 F.2d 302, 313 (1st  Cir. 1991) (similar),          ______    _______          cert. denied, 112 S. Ct. 986 (1992).          _____ ______                                          12          rested, asserting that,  though the three men  were lodged within          the same cell block, they did not share a cell.                    For  reasons that  are  somewhat  opaque, the  district          court  denied the motion  without a hearing  and without findings          anent the accuracy of  appellants' "three to a cell"  allegation.          Instead, the court  determined that, regardless of  the dormitory          arrangements, its sequestration  order had not been flouted.   It          is against this  rather spartan background that  we undertake our          analysis.8                                    A.  Rule 615.                                    A.  Rule 615.                                        ________                    The  sanctum  sanctorum   of  supervised  sequestration                         _______  _________          states in its salient segment:                         At  the request  of  a party  the  court                    shall order witnesses  excluded so that  they                    cannot hear the testimony of other witnesses,                    and it may make the order of its own motion.          Fed. R.  Evid. 615.   The rule  more or less  codifies common-law          sequestration powers, but  it is at  once less discretionary  and          less stringent  than its forebears.  On one hand, the rule cabins          the judge's discretion by affording  all parties a right to close                                                             _____                                        ____________________               8To recognize that the record  sheds no light on the factual          underpinnings of the  sequestration dispute is not to  imply that          the  defense lacked  opportunity to  explore  the possibility  of          sequestration  violations.    During  trial,  appellants   cross-          examined  all three witnesses  at length, inquiring,  inter alia,                                                                _____ ____          whether they had discussed the case with others.  The examination          elicited no  evidence that the trio traded tales concerning past,          present, or future  testimony.  Cf. United States  v. Eyster, 948                                          ___ _____________     ______          F.2d 1196, 1210 (11th  Cir. 1991) (finding that  witnesses housed          in  the same  cell  who admitted  discussing testimony  with each          other violated a sequestration order).  Moreover, appellants knew          all  along that  Perez, Milne,  and Coriaty  dwelled at  the same          penitentiary,  yet  they  made no  specific  inquiries  about the          congregant housing arrangement.                                          13          the  courtroom to  prospective witnesses.9   On  the other  hand,          while  the   common  law   supported  sequestration   beyond  the          courtroom, see 6 John Wigmore, Evidence   1840, at 471 n.7 (1976)                     ___                 ________          (stating  that, at common law, the sequestration process involves          three  parts:  preventing  prospective witnesses  from consulting          each  other; preventing  witnesses  from hearing  other witnesses          testify;  and preventing  prospective  witnesses from  consulting          witnesses  who have already  testified), Rule 615  contemplates a          smaller  reserve;  by  its terms,  courts  must  "order witnesses          excluded" only from the courtroom proper, see Perry v. Leeke, 488                                                    ___ _____    _____          U.S. 272,  281 & n.4  (1989); United States  v. Arruda,  715 F.2d                                        _____________     ______          671, 684 (1st Cir. 1983).  In  sum, the rule demarcates a compact          procedural heartland,  but leaves appreciable  room for  judicial          innovation  beyond  the   perimeters  of  that  which   the  rule          explicitly requires.   See United States v. De Jongh, 937 F.2d 1,                                 ___ _____________    ________          3  (1st  Cir.   1991)  (stating  that  district   courts  possess          "considerable  discretion"   to  fashion  orders   pertaining  to          sequestration).10                                        ____________________               9The  rule's  stringencies  in that  respect  have  not been          adopted by all states.  See  6 John Wigmore, Evidence   1837,  at                                  ___                  ________          458  n.11 (1976);  see also  id.  at 35  (Supp. 1991)  (compiling                             ___ ____  ___          data).    Rather,  many states  continue  to  leave sequestration          decisions solely within the judge's  discretion.  See, e.g., R.I.                                                            ___  ____          R. Evid. 615.               10Citing United States v. Greschner, 802 F.2d 373 (10th Cir.                        _____________    _________          1986),  cert. denied, 480  U.S. 908 (1987),  appellants postulate                  _____ ______          that Rule 615  requires sequestration beyond the  courtroom door.          Although Greschner does equate "circumvention" of Rule 615 with a                   _________          violation of the  rule itself, it concedes that  controlling such          circumvention  rests within the  district court's discretion    a          condition that clearly  does not apply to violations  of Rule 615          itself.    Id. at  375-76.    Thus,  Greschner fails  to  support                     ___                       _________                                          14                    Outside of the  heartland, the district court  may make          whatever provisions  it deems necessary  to manage trials  in the          interests of  justice, see  id., including  the sequestration  of                                 ___  ___          witnesses before, during,  and after their testimony,  see Geders                                                                 ___ ______          v.  United States,  425 U.S.  80, 87  (1976), and  compelling the              _____________          parties to present witnesses in a prescribed sequence, see United                                                                 ___ ______          States  v. Machor,  879  F.2d  945, 954  (1st  Cir. 1989),  cert.          ______     ______                                           _____          denied, 493 U.S. 1094 (1990).  Rule 615 neither dictates when and          ______          how this case-management power ought  to be used nor mandates any          specific   extra-courtroom  prophylaxis,   instead  leaving   the          regulation  of witness  conduct  outside  the  courtroom  to  the          district judge's discretion.  See United States v. Arias-Santana,                                        ___ _____________    _____________          964 F.2d  1262, 1266 (1st  Cir. 1992) (explaining that  a federal          trial court may  enter non-discussion orders at  its discretion);          see  also  Arruda,  715  F.2d  at 684  (holding  that  there  was          ___  ____  ______          "technically"  no  violation  of  sequestration  where  witnesses          conversed outside the courtroom).                    _______                    This  is not to say, however, that sequestration orders          which affect witnesses outside the courtroom are a  rarity.  As a          practical  matter,  district  courts  routinely  exercise   their          discretion  to augment Rule 615 by instructing witnesses, without          making  fine spatial distinctions,  that they are  not to discuss          their  testimony.     Indeed,  such  non-discussion   orders  are          generally  thought  to   be  a  standard  concomitant   of  basic          sequestration fare, serving to fortify the protections offered by                                        ____________________          appellants' thesis.                                          15          Rule 615.  See Perry, 488 U.S. at 281-82.                     ___ _____                         B.  Sequestration and Cohabitation.                         B.  Sequestration and Cohabitation.                             ______________________________                    Here,  appellants   moved  in  advance  of   trial  for          sequestration  without  indicating  to the  court  what  level of          restraint they thought appropriate.  The court granted the motion          in   its  simplest   aspect,   directing  counsel   "to   monitor          sequestration"  and ordering "that  witnesses who are  subject to          [the court's] order are not to be present in the courtroom at any          time prior to  their appearance to render testimony."   At trial,          the district court expanded its earlier order beyond the Rule 615          minimum,  instructing each  witness at  the close  of his  or her          testimony  not to discuss that  testimony with any other witness.          Appellants accepted the conditions of sequestration described  by          the court  without demurrer.  What is  more, they did not request          any further instructions, say, that witnesses  be directed at the          end of each  day, or  before each  recess, not  to discuss  their          testimony.    Thus,  every  witness was  placed  under  an  order          prohibiting discussion of the case with other witnesses only upon          the completion of his or her testimony.                    On these facts,  the district court's denial  of relief          must be  upheld.   The court's  basic sequestration order,  which          ploughed a straight furrow in line with Rule 615  itself, did not          extend beyond the  courtroom.  There has been  no intimation that          the witnesses  transgressed this  order.   Moreover, because  the          district  court  did   not  promulgate  a  non-discussion   order          applicable to any witness until  the conclusion of that witness's                                          16          testimony,  Perez, Milne, and  Coriaty were under  no obligation,          prior   to  that  moment,   to  refrain  from   discussing  their          recollections with  each other.   Finally,  there is no  evidence          that any of  the three ever chatted  about the case  with another          witness after having been admonished to the  contrary   or at any          earlier time, for that matter.                    Given this predicate, appellants' plaint reduces to the          unprecedented proposition  that witness  cohabitation constitutes          an automatic violation  of a standard  sequestration order.   The          crux   of  sequestration,   however,  is   communication  between          witnesses,  not shared  accommodations  or geographic  proximity.          Social  settings, such as communal  housing or common work sites,          may offer opportunities for witnesses to compare notes and gossip          about their testimony, but  such environments do not ensure  that          forbidden  conversations will occur.   We assume  that witnesses,          like all other  persons subject to court orders,  will follow the          instructions they receive.   Cf., e.g., Richardson  v. Marsh, 481                                       ___  ____  __________     _____          U.S. 200, 206  (1987) (reiterating the "invariable  assumption of          the law  that jurors follow  their instructions").   We conclude,          therefore, that  the housing arrangement,  in and of  itself, did          not violate an existing sequestration order.                    If  doubt inhered    and we see  no room for  any   two          other considerations would then be decisive.  In the first place,          a district court's interpretation of its own order is customarily          accorded great weight.  See, e.g., Witty v. Dukakis, 3  F.3d 517,                                  ___  ____  _____    _______          521  (1st Cir.  1993); Martha's  Vineyard Scuba  Hqtrs., Inc.  v.                                 ______________________________________                                          17          Unidentified,  Wrecked & Abandoned  Steam Vessel, 833  F.2d 1059,          ________________________________________________          1066-67 (1st  Cir. 1987); Lefkowitz  v. Fair, 816 F.2d  17, 22-23                                    _________     ____          (1st Cir. 1987).  Here,  the district court ruled that congregant          housing of witnesses did not  infringe on the sequestration  that          it decreed.  When a trial court's interpretation of its own order          tracks plain language  and the  actual sequence  of events,  that          interpretation must be honored on appeal.                    In  the  second place,  even  if  some implied  ban  on          congregant  housing of  prisoner-witnesses existed,  breach of  a          sequestration order would not automatically call for a new trial;          rather,  the need  for  a sanction,  and  the nature  of one,  if          imposable,  are  matters  committed to  the  trial  court's sound          discretion.  See United States v.  Rossetti, 768 F.2d 12, 16 (1st                       ___ _____________     ________          Cir.  1985); Arruda,  715 F.2d  at 684.   Appellants'  failure to                       ______          request  a   broader  sequestration   order,  coupled  with   the          speculative nature of their claim of actual prejudice, renders it          impossible  to find  an abuse  of  discretion here.   See,  e.g.,                                                                ___   ____          Rossetti, 768 F.2d at 16.          ________                    To  sum up,  our  search  of the  record  in this  case          discloses  no  reason  to  suspect  that  the  government or  its          witnesses  transgressed the existing sequestration order.  And as          we   have  indicated,  if  appellants  desired  a  more  vigorous          sequestration  regime, such  as an  edict that would  have banned          cohabitation or  other contact  amongst prisoner-witnesses,  they          had a  duty to ask for  it.  They failed  to do so.   Under these          circumstances,  the  district  court  appropriately  declined  to                                          18          overturn the  convictions.  See, e.g.,  De Jongh, 937  F.2d at 3;                                      ___  ____   ________          Rossetti, 768 F.2d  at 16; see also Langel v.  United States, 451          ________                   ___ ____ ______     _____________          F.2d 957, 963  (8th Cir. 1971) (determining that district court's          refusal  to  restrict  witnesses  from communicating  with  other          witnesses,  after some had  testified, did not  constitute error;          defendants made "no  showing . . . that  Government witnesses did          talk to each other after testifying").          IV.  DISPUTES ANENT DISCOVERY          IV.  DISPUTES ANENT DISCOVERY                    Appellants complain vociferously about the government's          conduct during discovery.  The  complaints have a modest basis in          fact.   Over the course  of this logistically complex  trial, the          government   produced  a  number  of  documents  in  a  seemingly          lackadaisical  fashion.    On each  of  these  occasions, defense          counsel had to scramble in  order to assess the nascent discovery          and integrate it into their  trial strategy.  On other occasions,          the  government refused to produce documents that defense counsel          believed were  discoverable either  as exculpatory  material, see                                                                        ___          Brady  v. Maryland,  373 U.S.  83, 87  (1963), or  as  fodder for          _____     ________          impeachment, see  Giglio v. United  States, 405 U.S.  150, 154-55                       ___  ______    ______________          (1972);  see  also  18  U.S.C.     3500  (1988)   (requiring  the                   ___  ____          government  to  disclose,  after  direct  testimony  and  on  the          defendant's   motion,  any  statement  by  the  witness,  in  the          government's  possession, that relates  to the subject  matter of          the  witness's  testimony).   We  discuss  these  two species  of          discovery problems separately.                                A.  Delayed Discovery.                                A.  Delayed Discovery.                                    _________________                                          19                    Prosecutors have  an obligation to  furnish exculpatory          and  impeachment information to the defense  in a timely fashion.          Although the  government's obligation goes beyond  the good-faith          requirement  of civil  discovery, see  United  States v.  Samalot                                            ___  ______________     _______          Perez,  767  F.2d  1, 4  (1st  Cir.  1985),  its  bounds are  not          _____          limitless.  Patrolling these boundaries is  primarily the duty of          the  nisi prius  court.   Because  the district  judge is  better               ____ _____          attuned to  the  nuances of  the trial,  this court  must take  a          deferential view of rulings made in the course of that patrol.                    When discovery  material makes a belated  appearance, a          criminal  defendant  must  ordinarily seek  a  continuance  if he          intends to claim prejudice.   A continuance affords time to study          the   newly   emergent   information,   consider   its   possible          ramifications, change trial  strategy (if necessary),  assess any          potential   prejudice,  and  determine   how  best  to   use  the          information.  As a general rule, a defendant who does not request          a  continuance will not  be heard to  complain on appeal  that he          suffered prejudice as a result of late-arriving discovery.   See,                                                                       ___          e.g., United States v. Osorio, 929 F.2d 753, 758 (1st Cir. 1991);          ____  _____________    ______          see also  United States v.  Diaz-Villafane, 874 F.2d 43,  47 (1st          ___ ____  _____________     ______________          Cir.)  (concluding, in an  analogous context, that  a defendant's          cry of unfair surprise "is  severely undermined, if not  entirely          undone,  by  his  neglect  to   ask  the  district  court  for  a          continuance to  meet the  claimed exigency"),  cert. denied,  493                                                         _____ ______          U.S. 862 (1989).  Thus,  in situations where defense counsel does          not  seek  a  continuance upon  belated  receipt  of discoverable                                          20          information, a court  often can assume that counsel  did not need          more time to incorporate the information into the  defense's game          plan.  See United States v. Ingraldi, 793 F.2d 408, 413 (1st Cir.                 ___ _____________    ________          1986).                    This general  rule spells  defeat for  the majority  of          appellants' delayed  discovery claims.   In  every instance  save          one, appellants eschewed a request  for a continuance.  They have          never satisfactorily  explained how  delays in production  caused          them  any  cognizable harm  on  those several  occasions  and the          record,  which  reflects  that  appellants  assimilated  the  new          material without  any  perceptible  hitch  and used  it  to  good          effect,  belies  any  such  claim.    The  lack  of  demonstrable          prejudice sounds the death knell for a "delayed discovery" claim.          See United States  v. Devin, 918  F.2d 280, 290  (1st Cir.  1990)          ___ _____________     _____          (explaining that  a defendant  who complains  about tardiness  in          disclosure  "cannot rely on wholly conclusory assertions but must          bear the burden of  producing, at the  very least, a prima  facie                                                               _____  _____          showing  of  a   plausible  strategic  option  which   the  delay          foreclosed").    Hence,  we  find  appellants' delayed  discovery          claims, with one exception, to have been waived.                    The   facts   referable  to   the   remaining  dilatory          disclosure  claim can be  succinctly summarized.   Perez not only          worked as a  courier for David Sepulveda, but  also supported his          own cocaine  habit by peddling  drugs.  After he  was apprehended          for selling cocaine,  Perez agreed to testify  against appellants          in  return for  the United  States Attorney's  help in  seeking a                                          21          reduced sentence.   Since Perez was the only witness who tied all          the  defendants  to  David Sepulveda's  illicit  enterprise,  his          testimony was extremely important to the government's case.                    When  defense lawyers  began cross-examining  Perez, it          became  apparent that  the  FBI  records  furnished  in  pretrial          discovery  did not  list Perez's  entire  repertoire of  criminal          convictions,   especially  those   stemming   from  state   court          proceedings and not reported to the FBI.  When Perez acknowledged          that a state probation officer had prepared a presentence  report          for a New Hampshire court,  appellants asked for a continuance so          that  they might  obtain  this document  and more  fully research          Perez's  criminal history.  The  district court denied the motion          but offered  to permit  the defense to  recall Perez  for further          cross-questioning should  the new  information warrant  it.   The          trial continued coincident  with the defense's efforts  to secure          the presentence report.                    After some travail, New Hampshire authorities agreed to          release the report to  the federal court in camera.  The district                                                   __ ______          judge  found  that it  contained  little  fresh material  but  he          nonetheless issued  a turnover order.   The defense  received the          report while  Perez was still  on the  witness stand.   The judge          refused to grant a mistrial  or afford appellants any  comparable          redress.                    We see no error.  The  prosecution was caught unawares;          it never knew of the report's existence and, therefore, could not          have deliberately withheld it.   Furthermore, the rigors of Brady                                                                      _____                                          22          do  not   usually  attach   to  material   outside  the   federal          government's  control   and the presentence  report at issue here          falls within  the scope  of this generality.   See,  e.g., United                                                         ___   ____  ______          States v.  Aichele, 941  F.2d 761, 764  (9th Cir.  1991) (holding          ______     _______          that  a  federal  prosecutor had  no  duty  to  procure materials          prepared  for  the state  courts which  were not  otherwise under          federal control).                    Last,  but far  from least,  delayed  disclosure claims          cannot  succeed  unless  the   aggrieved  defendant  demonstrates          prejudice arising  from the delay.   See  Devin, 918 F.2d  at 290                                               ___  _____          (refusing  to  reverse  conviction  where delayed  disclosure  of          impeachment  material  "had no  effect  on  the  outcome  of  the          trial"); Ingraldi, 793 F.2d at 411-12 (stating  that the critical                   ________          test "is whether defendant's  counsel was prevented by the  delay          from  using the disclosed  material effectively in  preparing and          presenting  the defendant's case").  Here, however, the defense's          delayed receipt of the report did not hinder cross-examination to          any appreciable degree.  From  the start of trial, appellants had          a  sizeable storehouse of data concerning Perez's checkered past.          In comparison  to  what  was  already known,  the  report,  which          yielded  a  relatively  inconsequential   amount  of  incremental          information, comprised small  potatoes.  Moreover, the  timing of          events  minimized  the  possibility  of  prejudice.    Appellants          received the report while Perez  was still testifying.  They were          able to incorporate its contents into their cross-examination and          employ the information effectively.   For aught that appears, the                                          23          course  and outcome  of the  trial would  have  been the  same no          matter when the report surfaced.                    In  our  view,  the  presider's  decision  to  allow  a          criminal case to  go forward, notwithstanding delayed  disclosure          of  material relevant  to  impeachment of  a  witness, should  be          upheld unless a  manifest abuse of discretion looms.   See Devin,                                                                 ___ _____          918 F.2d at  289.  On this  record, we can neither  criticize the          district court's exercise  of its informed discretion  nor tamper          with the court's  bipartite finding that the  government violated          no  duty  and  that,  in   any  event,  appellants  sustained  no          cognizable  prejudice  arising out  of  the  presentence report's          belated emergence.                                B.  Denied Discovery.                                B.  Denied Discovery.                                    ________________                    Appellants  also complain  that the court  below, after          scrutinizing  certain materials in camera, denied their motion to                                          __ ______          compel discovery.   The materials in question consist  of various          police files, including interview notes.   We have reviewed these          materials and  agree with the  lower court that they  are outside          the purview of the Jencks Act, 18 U.S.C.   3500, for two reasons.          First,  to be  discoverable  under the  Jencks Act,  a government          record of a  witness interview must  be substantially a  verbatim          account.  See United States v. Newton, 891 F.2d  944, 953-54 (1st                    ___ _____________    ______          Cir.  1989).   Second,  the  account  must  have been  signed  or          otherwise verified by the witness  himself.  See United States v.                                                       ___ _____________          Gonzalez-Sanchez,  825 F.2d 572, 586-87 (1st Cir.), cert. denied,          ________________                                    _____ ______          484 U.S. 989 (1987).  The  police files at issue here,  including                                          24          the interview notes,  do not meet either of  these guidelines and          are, therefore, non-discoverable.  A fortiori, the district court                                             _ ________          did not blunder in denying access to them.          V.  COCONSPIRATORS' STATEMENTS          V.  COCONSPIRATORS' STATEMENTS                    During the course  of trial, the judge  allowed several          witnesses to  attribute out-of-court  statements to  one or  more          declarants,   finding,  inter  alia,  that  the  declarants  were                                  _____  ____          coconspirators.  Appellants assign error.                    Although out-of-court statements made by non-testifying          declarants ordinarily are excluded as hearsay if offered to prove          the truth of the matter asserted, see Fed. R. Evid. 801(c), there                                            ___          are exceptions  to the rule.  One such exception provides that "a          statement by a coconspirator of a  party during the course and in          furtherance  of the  conspiracy" is  not hearsay.   Fed.  R. Evid          801(d)(2)(E).   To  invoke the  exception, a  party who  wants to          introduce  a particular statement must show by a preponderance of          the evidence that  a conspiracy embracing both  the declarant and          the  defendant  existed,  and  that  the  declarant  uttered  the          statement  during and  in  furtherance of  the  conspiracy.   See                                                                        ___          Bourjaily  v. United States, 483 U.S.  171, 175-76 (1987); Ortiz,          _________     _____________                                _____          966 F.2d at 714-15.  The party at whom the evidence is aimed must          object to the statement when it is offered; and,  if the district          court accepts  the evidence de bene,  must then ask  the court at                                      __ ____          the close of  all the relevant evidence to  strike the statement,          i.e., to consider  whether the proponent fulfilled  the requisite          ____          foundational requirements  by  a preponderance  of the  evidence.                                          25          See Ortiz,  966 F.2d at 715;  United States v.  Perkins, 926 F.2d          ___ _____                     _____________     _______          1271, 1283  (1st  Cir.  1991);  see generally  United  States  v.                                          ___ _________  ______________          Ciampaglia, 628 F.2d 632, 638  (1st Cir.), cert. denied, 449 U.S.          __________                                 _____ ______          956 (1980);  United States v.  Petrozziello, 548 F.2d 20,  23 n.3                       _____________     ____________          (1st Cir. 1977).                    On five occasions,  at least one defendant  objected to          testimony  anent coconspirators'  out-of-court statements.11   We          treat  these  objections as  fully  preserved    after  all,  the          district court  told counsel that  it deemed an objection  by one          defendant sufficient to  preserve the rights of  all defendants            and, accordingly, we  plumb the record in an  effort to determine          whether any or  all of the district court's  rulings with respect          to these statements were clearly erroneous.  See United States v.                                                       ___ _____________          McCarthy, 961  F.2d 972,  977 (1st Cir.  1992); United  States v.          ________                                        ______________          Cresta, 825 F.2d 538, 551 (1st Cir. 1987), cert. denied, 486 U.S.          ______                                     _____ ______          1042 (1988).                    We  begin  by  considering three  pieces  of  testimony          recounting out-of-court statements.  The common thread that joins          these proffers is that the government adduced some other evidence          tending   to   prove   that  the   declarants   were,   in  fact,          coconspirators.  We then address two pieces of testimony that are          not cushioned in a comparable fashion.                              A.  Supported Statements.                              A.  Supported Statements.                                  ____________________                                        ____________________               11On a sixth occasion, defendant Driesse objected to another          statement.   Inasmuch as that statement implicated Driesse alone,          we regard the  ensuing assignment of error as beyond the scope of          this opinion.  See supra note 2.                         ___ _____                                          26                    1.     Milne  Testimony.     Milne  (a   self-confessed                    1.     Milne  Testimony.                           ________________          coconspirator) served as  the wellspring of the  first statement.          He testified  that a defendant,  Edward Welch, told him  that the          police  noticed cocaine  on his  (Welch's) bed  in the  course of          executing a  search warrant.   The district court found  that the          declarant, Welch, was a coconspirator, and that Welch's statement          was  made during  and  in  furtherance of  the  conspiracy.   The          finding is fully sustainable.                    Both Coriaty and  Milne testified that Welch  sold them          cocaine he  had purchased  from David  Sepulveda (an  arrangement          that  numerous  other  witnesses  corroborated).   This  evidence          encourages,  if it  does not  demand, the  conclusion  that Welch          worked hand  in glove with  Sepulveda.   A pattern of  drug sales          between  two individuals, looking toward resale to third persons,          together  with  appropriate  contextual  detail,  can  support  a          finding that the two individuals were jointly involved in a drug-          trafficking conspiracy.   See  United States  v. Moran,  984 F.2d                                    ___  _____________     _____          1299, 1303 (1st Cir. 1993); United States v. Glenn, 828 F.2d 855,                                      _____________    _____          857-58  (1st  Cir. 1987).    The  record likewise  justifies  the          conclusion that Welch's statements to Milne were made  during and          in furtherance of the conspiracy.  We think it is common ground            and common  sense   that  the reporting of significant  events by          one coconspirator to another advances the conspiracy.  See United                                                                 ___ ______          States v. Smith, 833 F.2d 213, 219 (10th Cir. 1987).          ______    _____                    2.  Rice  Testimony.  Another government  witness, John                    2.  Rice  Testimony.                        _______________          Rice, testified  that one  defendant, Driesse,  mentioned that  a                                          27          second  defendant, Rood, sold cocaine for the Sepulveda brothers.          The jury  found both  Driesse and Rood  guilty of  the conspiracy          charge,  and the  record gives  considerable  definition to  both          men's links to the drug ring.   And, moreover, since the  sharing          of pertinent information  about a conspiracy's mode  of operation          furthers  the conspiratorial ends,  see United States  v. Munson,                                              ___ _____________     ______          819 F.2d 337, 341 (1st Cir. 1987), Driesse's statement concerning          drug sales  assisted the  charged conspiracy  by informing  other          coconspirators of Rood's role and activities.                    3.    Malone Testimony.    A  third statement  came  in                    3.    Malone Testimony.                          ________________          through  a police  officer, Kathy  Malone, who  made a  number of          undercover  buys from Sepulveda-supplied  vendors.  She testified          that David Sepulveda's inamorata, Bambi Burley, told her that she          (Bambi) had  jilted Sepulveda and  asked whether Malone  might be          "one of those girls that went to  New York with him."  Appellants          challenge the admission of this statement on the sole ground that          Burley,  herself, was  a  stranger  to  the  charged  conspiracy.          However,  this  challenge  overlooks  Perez's testimony  that  he          collected drug debts for David  Sepulveda and delivered the money          to  Burley.   While  there  is  hardly  a profusion  of  evidence          depicting Burley as a coconspirator, there is enough to withstand          clear error review.12                                        ____________________               12It seems  problematic whether  these statements  furthered          the  conspiracy.   We need  not mull  this question,  however, as          appellants did not advance this  ground either in the lower court          or in their briefs.  The issue is, therefore, waived.  See United                                                                 ___ ______          States v. Slade, 980 F.2d 27, 31 (1st Cir. 1992).  In all events,          ______    _____          the statements seem harmless.                                          28                             B.  Unsupported Statements.                             B.  Unsupported Statements.                                 ______________________                    The two additional  instances in which the  court below          admitted  statements  under the  coconspirator  exception despite          contemporaneous objection are  qualitatively different.  In  each          instance, there appears to be  no record evidence, other than the          statement itself, to support its admissibility.                    One statement arose during the government's examination          of  a police  detective, Mark  Putney.   The detective  testified          that, while executing a search  warrant at a dwelling occupied by          defendant Cheryl Johnson and her  husband, Brian, he answered the          telephone:                    The  male caller asked if  Brian was home.  I                    stated  I was Brian.   The caller  stated did                    you pick  up the stuff.   I said I did.   The                    caller asked if  he could come over  and pick                    up a half.  I stated sure, come on over.                    The other statement occurred  during direct examination          of  Joseph  Baranski.    Baranski  testified  that  he  sometimes          provided  transportation for  people going  to David  Sepulveda's          house and that,  on occasion, his passengers would  tell him that          they were  visiting Sepulveda  because "they  wanted to  buy some          drugs."                    Our  review of the  record has deterrated  no extrinsic          evidence  tending to show that these out-of-court declarants (the          unidentified caller to the Johnson residence and the unidentified          passengers   in  Baranski's   vehicle)  were   involved  in   the          conspiracy, and the government has  directed us to no such proof.          Following  the Supreme Court's landmark opinion in Bourjaily, and                                                             _________                                          29          Justice Stevens's concurrence, 483 U.S.  at 185 & n.2, several of          our  sister circuits  have concluded  that  the preponderance  of          evidence  required  for  the   introduction  of  an  out-of-court          statement under Rule 801(d)(2)(E) must  necessarily comprise more          than  the weight  of the  statement  itself.   See, e.g.,  United                                                         ___  ____   ______          States  v. Gambino,  926 F.2d  1355,  1361 n.5  (3d Cir.),  cert.          ______     _______                                          _____          denied, 112 S. Ct. 415 (1991); United States v. Garbett, 867 F.2d          ______                         _____________    _______          1132, 1134 (8th Cir. 1989);  United States v. Silverman, 861 F.2d                                       _____________    _________          571, 577  (9th Cir.  1988); United States  v. Zambrana,  841 F.2d                                      _____________     ________          1320, 1344-45  (7th Cir. 1988);  see also United States  v. Daly,                                           ___ ____ _____________     ____          842 F.2d 1380, 1386 (2d Cir.), cert. denied, 488 U.S. 821 (1988).                                         _____ ______          We have not yet spoken to the point.  See, e.g., United States v.                                                ___  ____  _____________          Dworken, 855 F.2d 12, 25 (1st Cir. 1988) (deferring resolution).          _______                    This case presents the issue squarely and requires that          we decide it.  We hold that a coconspirator's statement, standing          alone, is insufficient to meet the preponderance standard of Rule          801(d)(2)(E).   In  other words,  to  satisfy the  weight-of-the-          evidence criteria for that hearsay exception, there must be  some          proof  aliunde.    Though  the  district  court  may  consider  a                 _______          statement's  contents   and  the   circumstances  attending   its          utterance  when gauging  the statement's reliability,  see United                                                                 ___ ______          States v.  Gomez-Pabon, 911  F.2d 847, 856  n.3 (1st  Cir. 1990),          ______     ___________          cert. denied,  498 U.S. 1074 (1991), admitting the statement into          _____ ______          evidence  requires  some  extrinsic   proof  of  the  declarant's          involvement  in the  conspiracy.   Thus,  because the  government          developed  no independent evidence of who Brian Johnson's callers                                          30          or Joseph  Baranski's passengers might  have been, or  what their          status  might have  been vis-a-vis  the  charged conspiracy,  the          statements  were  improperly  admitted  under  the  coconspirator          exception to the hearsay rule.13                    There   is  no  bright-line   rule  for  divining  when          particular errors that  result in a  jury's exposure to  improper          evidence are  (or  are not)  harmless.   Rather,  a  harmlessness          determination   demands   a  panoramic,   case-specific   inquiry          considering,  among other things,  the centrality of  the tainted          material, its  uniqueness, its  prejudicial impact,  the uses  to          which it was put during the trial, the relative  strengths of the          parties'  cases,  and any  telltales  that furnish  clues  to the          likelihood that the error affected the factfinder's resolution of          a  material issue.   Gearing  our inquiry  along these  lines, we          conclude that the errors in admitting  the statements are benign.          The  telephone  talk  concerned a  peripheral  matter,  for Brian          Johnson  was  not  on  trial.    Furthermore,  several  witnesses          testified at first  hand that his  wife and housemate,  appellant          Cheryl Johnson,  trafficked in  cocaine.   See supra  Part II(D).                                                     ___ _____          The passengers'  remarks constituted cumulative  evidence.   They                                        ____________________               13We  do not mean to imply  that the evidence might not have          been introduced for  some other purpose.   Suppose, for  example,          that the telephone calls Putney received were not offered to show          that someone in fact sought to buy drugs from Brian Johnson, but,          rather,  to  show  the  types  of telephone  calls  the  Johnsons          received.  If admissible on  that basis, the statements would not          be excludable as  hearsay.  See  Fed. R. Evid.  801(c); see  also                                      ___                         ___  ____          United  States  v.  Green,  887  F.2d  25,  27  (1st  Cir.  1989)          ______________      _____          (upholding  admission of out-of-court  statement to  show motive,          not for the truth of the matter asserted).                                          31          inculpated only David Sepulveda, and a googol of witnesses tabbed          Sepulveda  as  a  large-scale   narcotics  distributor  who  made          countless  cocaine sales.  Several  of these witnesses swore that          they  personally purchased drugs  from him.   Against  this tidal          wave  of  evidence,  Baranski's  testimony  was  a  drop  in  the          proverbial bucket.   Because  the record  offers every  assurance          that  the errant statements  did not affect  the trial's outcome,          they were harmless.14  See  United States v. Ladd, 885 F.2d  954,                                 ___  _____________    ____          957-58 (1st Cir. 1989); Dworken, 855 F.2d at 26.                                  _______          VI.  EXPERT TESTIMONY          VI.  EXPERT TESTIMONY                    At  trial,  the  government's  case culminated  in  the          testimony of Commander  Richard Gerry of  the New Hampshire  Drug          Task Force.   Before  Commander Gerry  testified, the  prosecutor          told the  court that Gerry's views would  be based upon the trial          testimony and his experience  as a police officer,  and predicted          that Gerry would "explain to the jury how the quantities of drugs          . . . referred to in the . . . testimony at trial [were] used and          distributed  . .  . from  the business  aspect."   Based  on this          representation, the court denied appellants' motion in limine and                                                              __ ______          permitted the witness to testify.                                         ____________________               14Appellants  also assign error to four statements that were          admitted without objection.  Absent a showing of plain error, the          failure  to object  below  is  fatal  to claims  that  particular          evidence should not have reached  the jury.  See Ortiz,  966 F.2d                                                       ___ _____          at 715; Perkins, 926 F.2d at 1283; see also Fed. R. Evid. 103(a).                  _______                    ___ ____          We find  no plain error in  connection with the admission  of the          four  statements; their introduction, whether viewed singly or in          combination, did not  "seriously affect the fundamental  fairness          and basic integrity  of the [trial],"  United States v.  Griffin,                                                 _____________     _______          818 F.2d 97, 100 (1st Cir.),  cert. denied, 484 U.S. 844  (1987),                                        _____ ______          or otherwise impair appellants' substantial rights.                                          32                    In  the initial stages, the testimony went according to          plan:  Commander  Gerry discussed the ways in  which drug dealers          commonly package their products and reviewed the economics of the          cocaine trade (illustrating the profit to be gained by buying and          selling  in various quantities).   Despite this  promising start,          matters  soon deteriorated.    Although Commander  Gerry  offered          opinions   as   to   appellants'   roles   in   the   enterprise,          characterizing David  Sepulveda as  "top dog"  and the  others as          rank-and-file  members  of  the  organization,  cross-examination          revealed that  these opinions  were less the  fruit of  an expert          mind  attuned to  the  testimony in  the case  than the  yield of          undifferentiated conversations over  the years with  unidentified          police  officers  regarding  Sepulveda and  his  associates.   So          ingrained were  the roots of  Commander Gerry's opinions  that he          was unable to specify the sources  of his information or, in  the          end, articulate a plausible basis for his views.  The speculative          nature  of Gerry's  testimony became  starkly  apparent when  the          defense established that he had heard only bits and pieces of the          testimony  in the  case.   These rather  startling insights  cast          grave doubt  upon both  the adequacy of  the foundation  on which          Gerry's testimony rested  and the existence of a fair opportunity          for effective cross-questioning.                    Midway through  cross-examination the defense  moved to          strike  the  expert's  testimony in  toto.    The district  court                                           __  ____          granted  the  motion.   We  think  the  defects in  the  expert's          presentation warranted this step.   Fed. R. Evid. 705 provides in                                          33          pertinent part  that an expert witness "may .  . . be required to          disclose  [on cross-examination] the underlying facts or data" on          which  his opinions rest.   If cross-examination reveals that the          opinions  advanced  by  an  expert rest  on  a  wholly inadequate          foundation,  the  judge,   on  timely  motion,  may   strike  the          testimony.  See, e.g., United States v. Scop, 846 F.2d 135,  142-                      ___  ____  _____________    ____          43 (2d Cir. 1988); Benjamin  v. Peter's Farm Condo. Owners Ass'n,                             ________     ________________________________          820 F.2d 640, 641 (3d Cir. 1987); see also 3 David W. Louisell et                                            ___ ____          al., Federal Evidence   400, at 709-10 (1979).               ________________                    The district judge also told  the jury to disregard the          offending testimony "entirely."  His instruction was firm, clear,          and to  the point.  Appellants  neither objected to  its form nor          sought to have the judge improve upon it.  The next day, however,          appellants moved  for a mistrial.   The judge denied  the motion.          On appeal, appellants  lament the denial  of both their  original          motion in limine and their subsequent motion for a mistrial.                 __ ______                              A.  The Motion in Limine.                              A.  The Motion in Limine.                                  ____________________                    The admission of  expert testimony is governed  by Fed.          R. Evid. 702,  which authorizes the district court  to admit such          testimony if, and to  the extent that, it will  "assist the trier          of fact  to understand  the evidence  or to  determine a  fact in          issue  .  .  . ."    Id.   Because  gauging  an  expert witness's                               ___          usefulness  is almost  always a  case-specific  inquiry, the  law          affords trial  judges substantial  discretion in  connection with          the admission or  exclusion of opinion evidence.   See Apostol v.                                                             ___ _______          United States, 838  F.2d 595, 599 (1st Cir.  1988); United States          _____________                                       _____________                                          34          v. Hoffman, 832 F.2d 1299, 1310 (1st Cir. 1987); see also  3 Jack             _______                                       ___ ____          Weinstein & Margaret A. Berger, Weinstein's Evidence   702[02] at                                          ____________________          702-22 to 702-23 (1993).  It follows that a trial judge's rulings          in  this sphere should  be upheld "unless  manifestly erroneous."          Salem v. United  States Lines Co.,  370 U.S.  31, 35 (1962);  see          _____    ________________________                             ___          also Hoffman, 832  F.2d at  1310 (explaining  that "the  district          ____ _______          court's assessment of what  will or will not  assist the jury  is          entitled to considerable deference in the Rule 702 milieu").                    Given the government's  preliminary proffer, there  was          no need for outright exclusion of the anticipated testimony.  The          Supreme Court has recently reaffirmed that when a  party proffers          an  expert,  the  trial judge  performs  a  gatekeeping function,          determining  whether  it  is reasonably  likely  that  the expert          possesses specialized  knowledge  which  will  assist  the  trier          better to understand a fact in issue.  See Daubert v. Merrell Dow                                                 ___ _______    ___________          Pharmaceuticals, Inc.,  113  S.  Ct.  2786,  2796  (1993).    The          _____________________          witness's opinions need  "not [be] based on  first-hand knowledge          or observation."  Id. at 2796.                            ___                    Seen  in light of these authorities, the district court          had  a reasonable basis for  allowing the expert  to testify.  If          Commander  Gerry's pedagogy  proved  to  be  as  advertised,  his          testimony  arguably would have assisted the jury in understanding          the   voluminous  evidence   that  had   emerged.     Experienced          investigators are  commonly permitted  to testify  as experts  on          topics  such  as the  structure  of  a  criminal enterprise,  the          economics  of the  drug trade,  and the  handling of  contraband.                                          35          See, e.g., United States v.  Angiulo, 897 F.2d 1169, 1188-89 (1st          ___  ____  _____________     _______          Cir.) (allowing veteran FBI agent to offer opinions, based mainly          on information  presented at  trial, about  defendants' roles  in          gambling ring), cert. denied, 498 U.S. 845 (1990); Ladd, 885 F.2d                          _____ ______                       ____          at  959 (allowing  experienced police  officer  to testify  about          methods of packaging  and processing heroin, and  relationship to          distribution  venture); United States  v. Angiulo, 847  F.2d 956,                                  _____________     _______          973-75  (1st Cir.) (allowing suitably credentialed agent to offer          expert opinions about structure and operation of La Cosa  Nostra,          including defendants' relationships  to that organization), cert.                                                                      _____          denied, 488 U.S. 928 (1988);  Hoffman, 832 F.2d at 1310 (allowing          ______                        _______          knowledgeable federal  agent  to  testify as  an  expert  on  the          practices and idiom of the cocaine community).                    In  sum, the  lower  court's denial  of  the motion  in                                                                         __          limine cannot be  faulted.  The unhappy fact  that, in hindsight,          ______          the expert turned out  to be a dud does not  retroactively negate          the lawfulness  of the  court's original  ruling.   Trial judges,          whose lot is often to make swift battlefield decisions on tangled          evidentiary  matters, cannot be  expected to foretell  the future          with absolute accuracy.15                              B.  The Motion for Mistrial.                              B.  The Motion for Mistrial.                                  _______________________                                        ____________________               15When  uncertainty attends a  proffer of  opinion evidence,          voir dire screenings are standard  fare.  See, e.g., Tokio Marine          ____ ____                                 ___  ____  ____________          & Fire Ins. Co. v. Grove Mfg. Co., 958 F.2d 1169, 1175 & n.4 (1st          _______________    ______________          Cir. 1992);  Freeman v.  Package Mach. Co.,  865 F.2d  1331, 1337                       _______     _________________          (1st Cir. 1988); cf. United  States v. Griffin, 818 F.2d 97,  105                           ___ ______________    _______          (1st Cir.)  (discussing  utility of  voir  dire in  an  analogous                                               ____  ____          context), cert.  denied,  484  U.S. 844  (1987).    But  although                    _____  ______          appellants moved  in limine  to forfend  Gerry's testimony,  they                            __ ______          apparently never sought permission to conduct a voir dire.                                                          ____ ____                                          36                    Appellants'  next   assignment  of  error   presents  a          slightly closer  question.   Although the  district court  struck          Commander Gerry's half-completed testimony and told the jurors to          disregard what they had heard,  appellants assert that the  court          erred  in  refusing  to  grant  a  mistrial.    At  the  core  of          appellants' argument lies their insistence that  the judge did no          more  than hold a farthing candle to  the sun; once Gerry's views          were aired,  words from the  bench, no matter how  stentorian the          judge's tone, could not exorcise the resultant prejudice.                    Granting or denying a motion for a mistrial is a matter          committed to  the trial  court's discretion.   See De  Jongh, 937                                                         ___ _________          F.2d at 3; United  States v. Chamorro, 687 F.2d 1,  6 (1st Cir.),                     ______________    ________          cert.  denied,  459 U.S.  1043  (1982).    The exercise  of  that          _____  ______          discretion always  must be informed  by the circumstances  of the          particular case.   When, as now, a  motion to declare  a mistrial          has its genesis in a claim that improper evidence came before the          jury, the court must first weigh the claim of impropriety and, if          that claim is well founded, strike the offending evidence.  Next,          unless   the  court  believes  that  the  evidence  is  seriously          prejudicial   and  that  a   curative  instruction  will   be  an          insufficient  antidote, the court  should proceed with  the trial          after instructing the jury to disregard the  evidence.  Declaring          a mistrial is  a last resort, only to be implemented if the taint          is ineradicable, that  is, only if the trial  judge believes that          the jury's  exposure to  the evidence is  likely to  prove beyond          realistic hope of repair.                                          37                    In this  instance, Judge  Devine followed the  standard          paradigm as closely as possible, considering appellants' delay in          offering the mistrial motion.   Three factors persuade us that he          handled  the situation in  an appropriate manner.   First, courts          have long recognized that, within wide margins, the potential for          prejudice stemming  from improper  testimony or  comments can  be          satisfactorily  dispelled by  appropriate curative  instructions.          See, e.g.,  United States v.  Figueroa, 900 F.2d 1211,  1216 (8th          ___  ____   _____________     ________          Cir.),  cert. denied,  496  U.S.  942  (1990); United  States  v.                  _____ ______                           ______________          Ferreira,  821 F.2d  1, 5-6  (1st  Cir. 1987);  United States  v.          ________                                        _____________          Cirrincione, 780 F.2d 620, 635 (7th Cir. 1985).  The instructions          ___________          given here pass  the test of appropriateness;  indeed, appellants          have  not  suggested  any  way  in which  they  might  have  been          improved.                    Second, Judge  Devine did  not allow  sores to  fester.          Rather,  he halted Commander  Gerry's testimony in  midstream and          instructed the jurors to discard  the faulty evidence.  Swiftness          in  judicial  response  is an  important  element  in alleviating          prejudice once the  jury has been exposed  to improper testimony.          See,  e.g., United  States v.  Pryor, 960 F.2d  1, 2-3  (1st Cir.          ___   ____  ______________     _____          1992); United  States v. Hernandez,  891 F.2d 521, 523  (5th Cir.                 ______________    _________          1989), cert.  denied, 495 U.S.  909 (1990).   In  this case,  the                 _____  ______          judge could scarcely have acted more celeritously.                    Third,    appellate   courts    inquiring   into    the          effectiveness  of  a trial  judge's curative  instructions should          start  with  a  presumption  that jurors  will  follow  a  direct                                          38          instruction  to disregard  matters  improvidently brought  before          them.  See  United States v. Olano, 113 S. Ct. 1770, 1781 (1993);                 ___  _____________    _____          Richardson, 481 U.S.  at 206.  Though rebuttable, the presumption          __________          endures  unless it appears  probable that, in  a particular case,          responsible jurors will not  be able to put the testimony  to one          side, and, moreover, that the testimony  will likely be seriously          prejudicial to the aggrieved party.   See United States v. Paiva,                                                ___ _____________    _____          892 F.2d 148, 160 (1st Cir. 1989) (collecting cases).                    Read as a whole,  Commander Gerry's partially completed          testimony does  not strike  us as so  compelling that  its impact          would linger  even  after  the  court's stern  admonition.    The          testimony is virtually  indistinguishable from the vast  array of          other  evidence introduced by the prosecution, and, therefore, it          is  of  the  cumulative  vintage.16    We  have  routinely  found          cumulative evidence  impotent when  accidentally uncorked.   See,                                                                       ___          e.g., United States v. Ellis, 935 F.2d 385, 393 (1st Cir.), cert.          ____  _____________    _____                                _____          denied, 112 S. Ct. 201 (1991); United States v. Morris, 700  F.2d          ______                         _____________    ______          427, 431 (1st Cir.), cert. denied, 461 U.S. 947 (1983).  So it is                               _____ ______          here.   Appellants have not successfully rebutted the presumption          that the jury heeded the judge's instructions.                    In a last-ditch effort to save the day, appellants come          at the question  of undue prejudice from a  slightly more oblique                                        ____________________               16It  is,  perhaps,  worth noting  that  the  only defendant          discussed in  any detail by the  witness was David Sepulveda    a          defendant   as  to  whom  the  prosecution  adduced  overwhelming          evidence of  guilt.  We  add that, although there  were different          quanta of evidence as to  each defendant, a painstaking review of          the  record inspires  confidence that  Gerry's  testimony had  no          significant spillover effect vis-a-vis other defendants.                                          39          angle.     They  allege  that  the  government's  questioning  of          Commander Gerry went  so far beyond the limits  of propriety that          putting  him on  the  witness  stand  amounted  to  prosecutorial          misconduct.    But  the  record  simply  does  not  support  this          accusation.  The government  had a reasonable basis for  offering          Gerry as an expert  witness.  Although  the decision did not  pan          out, that is no  reason to consign either  the prosecutor or  the          prosecution to the juridical equivalent of  philotheoparoptesism.          Like judges,  prosecutors cannot be  held to a standard  of utter          prescience.17                     For these reasons, we discern no abuse of discretion in          either  the  district  court's  initial  admission  of  Commander          Gerry's  testimony or the  court's refusal to  declare a mistrial          after  the  necessity  to  strike  the testimony  arose.    In  a          nutshell, there was no reason to  believe that the infelicitously          offered evidence  remained  in the  jurors'  minds after  it  was          banished from the case, and,  consequently, no need for the court          to jettison the baby when the bath water turned tepid.          VII.  CLOSING ARGUMENT          VII.  CLOSING ARGUMENT                    Appellants  contend  that   the  prosecutors'  comments                                        ____________________               17Moreover,  if blame  is to  be  assigned, appellants  must          share in it.  They could have,  but did not, ask for a voir dire.                                                                 ____ ____          See supra note 15.   A party who elects not to  request voir dire          ___ _____                                               ____ ____          of an opponent's  expert runs certain risks.   When a predictable          risk materializes,  there is little  incentive for  courts to  be          sympathetic.    Cf., e.g.,  Paterson-Leitch Co.  v. Massachusetts                          ___  ____   ___________________     _____________          Mun.  Wholesale Elec.  Co., 840  F.2d  985, 989  (1st Cir.  1988)          __________________________          ("Courts, like the Deity, are most frequently moved to help those          who help themselves.").                                          40          during closing argument constituted reversible error because some          statements spotlighted appellants' joint  decision not to testify          and others  unfairly inflamed  the jury's  passions.18   Although          these  contentions  are   obviously  related,  we  analyze   them          separately.                         A.  Comments on Defendants' Silence.                         A.  Comments on Defendants' Silence.                             _______________________________                    We begin with bedrock.  The Fifth Amendment forbids any          comment  by the  prosecutor on  the defendant's  exercise of  the          right  to remain silent.  See United States v. Robinson, 485 U.S.                                    ___ _____________    ________          25, 30 (1988);  Griffin v. California, 380 U.S.  609, 615 (1965).                          _______    __________          The proposition is more easily stated than applied.   There is no          bright line marking the precipice between a legitimate assessment          of defense witnesses  and an impermissible encroachment  upon the          accused's silence.  Prosecutors who choose to explore such rugged          terrain must  take particular care  not to comment upon,  or call          the  jury's  attention to,  a  defendant's  failure  to take  the          witness stand.  See  United States v.  Lavoie, 721 F.2d 407,  408                          ___  _____________     ______          (1st Cir.  1983), cert. denied, 465 U.S.  1069 (1984); Rodriguez-                            _____ ______                         __________          Sandoval v. United States, 409 F.2d 529, 531 (1st Cir. 1969).          ________    _____________                    Nonetheless, the road runs in both directions,  leading          to a  rough mutuality  of obligation.   Defense attorneys  have a          responsibility to  exercise reasonable  vigilance and direct  the          trial court's immediate  attention to perceived trespasses.   See                                                                        ___          generally Ortiz, 966  F.2d at 715  (pointing out that  "attorneys          _________ _____                                        ____________________               18We  use "prosecutors" in the plural because one government          attorney delivered  the  initial summation  and  another  handled          rebuttal.                                          41          must  usually   bear  the  responsibility  for  preserving  their          points"); United States  v. Griffin, 818 F.2d 97,  100 (1st Cir.)                    _____________     _______          (discussing the "obligation to alert the district judge to error-          in-the-making"), cert.  denied, 484  U.S. 844  (1987).   Although                           _____  ______          excessive  summations  may  on  rare  occasions constitute  plain          error,  redressable after the fact notwithstanding the absence of          a  contemporaneous  objection,  see,  e.g.,  Arrieta-Agressot  v.                                          ___   ____   ________________          United  States, 3  F.3d  525,  528 (1st  Cir.  1993), a  criminal          ______________          defendant  who believes that a prosecutor's closing argument goes          too far must usually object  to the offending statements when and          as they are  uttered.  See id.  In this  way, the prosecution can                                 ___ ___          clarify  ambiguities and correct mislocutions in a timely manner,          and,  if necessary, the  trial judge can  administer an immediate          antidote, thereby curtailing any damage.                    None of the appellants chose to testify at trial.  Yet,          the prosecutors courted trouble in both segments of their closing          argument.  Initially, one of them asked rhetorically:                    Did anyone come  into this courtroom and  say                    what the Government witnesses told you didn't                    happen?    Did  they?    They   attacked  the                    witnesses, the DEA, the police officers, [and                    the government attorneys]. . . .          On rebuttal, her colleague expanded upon (and twice repeated) the          same theme:                    The  United   States  introduced  a   lot  of                    evidence during  this trial, a  lot of facts.                    And for the  most part, there is  no evidence                    in  this case to show that what our witnesses                    said happened did  not happen.  That  is, the                    defendants  have  done little  or  nothing to                    refute that evidence.                                          42                                 *        *        *                    Ladies  and   gentlemen,  we  stand   on  the                    evidence,  the  overwhelming   evidence,  the                    evidence  which,  for  the   most  part,  the                    defendants  have done  absolutely nothing  to                    refute . . . .          It was only  after the jury had  been dismissed for the  day that          appellants, having sat  silently throughout both segments  of the          prosecutors'  summations, moved for  a mistrial based  in part on          the  quoted statements.   The  trial court  denied the  motion as          untimely and sent the case to the  jury the next morning.  In the          course  of  the charge,  Judge  Devine  stated on  five  separate          occasions  that the government  was responsible for  carrying the          burden  of proof,  that the  defendants had  the right  to remain          silent,  and  that  no  inferences   might  be  drawn  from   the          defendants' election not to testify.19                    In  assaying  the  appropriateness  of  a  prosecutor's          remarks,  context  frequently  determines meaning.    See,  e.g.,                                                                ___   ____          United States v.  Young, 470 U.S. 1, 11  (1985); United States v.          _____________     _____                          _____________          Akinola, 985  F.2d 1105, 1111  (1st Cir. 1993); United  States v.          _______                                         ______________          Lilly, 983 F.2d 300, 307 (1st Cir. 1992).   Once the prosecutor's          _____          words are  placed in context,  we inquire  whether "the  language          used was  manifestly intended or  was of such character  that the          jury  would naturally and necessarily take  it to be a comment on                                        ____________________               19To be sure, the judge did not specifically direct the jury          to disregard the comments quoted above.   Yet, appellants neither          sought such an instruction nor objected to its  absence.  A trial          court's  failure to launch  a limiting instruction  sua sponte is                                                              ___ ______          not  reversible error.  See,  e.g., United States  v. De La Cruz,                                  ___   ____  _____________     __________          902 F.2d 121,  134 (1st Cir. 1990); Rivera-Santiago,  872 F.2d at                                              _______________          1083.                                          43          the failure of the accused to testify."  United States v. Glantz,                                                   _____________    ______          810  F.2d 316, 322 (1st Cir.)  (citations omitted), cert. denied,                                                              _____ ______          482 U.S.  929 (1987);  see also  Lilly, 983  F.2d at  307.20   In                                 ___ ____  _____          borderline  cases, the standard of review can figure importantly.          When  no contemporaneous objection  appears of  record, appellate          review is for plain error.  See Arrieta-Agressot, 3 F.3d at  528;                                      ___ ________________          United States v. Smith,  982 F.2d 681, 682  (1st Cir. 1993);  see          _____________    _____                                        ___          also  Fed.  R.  Crim.  P.  52(b).    And  in  the  absence  of  a          ____          contemporaneous objection it  seems fair to  give the arguer  the          benefit  of every  plausible interpretation  of her  words.   See                                                                        ___          United States  v. Donlon, 909  F.2d 650, 656-57 (1st  Cir. 1990);          _____________     ______          Glantz,  810 F.2d  at 323; cf.  Robinson, 485 U.S.  at 31 (noting          ______                     ___  ________          that counsel's failure to object contemporaneously suggests  that          the arguer's statement is not ambiguous).                    In  this  case,  the  prosecutors'  remarks,  taken  in          context and at face value, do not  appear to constitute a comment          on  the accuseds'  silence.   The  government's closing  argument          recounted  the  evidence   against  each  defendant  and,   while          admitting that  certain prosecution witnesses  possessed unsavory          reputations  and might  profit  by cooperation,  the  prosecutors          urged the jury to find that those witnesses testified truthfully.          Not  surprisingly,  defense  counsels' summations  played  up the                                        ____________________               20In  this case,  the  district  court  apparently  did  not          believe  that  the  prosecutors  intended  the  statements  as  a          reflection on the  defendants' failure to testify  and appellants          have not imputed so malign a motive  to the prosecution team.  We          focus,  therefore,  on  what  the   jury  might  have  taken  the          statements to imply.                                          44          credibility theme, systematically  besmirching the reliability of          the government's  witnesses, stressing  internal inconsistencies,          and  outlining  perceived  conflicts  between  the  testimony  of          different witnesses.  Throughout, counsel paraded the cooperating          witnesses' criminal records  past the jury and made  much of what          those  witnesses  stood  to  gain  by  currying  favor  with  the          authorities.                    Visualized   against  this   backdrop,  and   assigning          ordinary  words their  most  natural  meaning, the  prosecution's          argument  that   the  defense   had  not   successfully  rebutted          incriminating  evidence seems not to be  a comment on appellants'          failure to  testify but  a comment about  the credibility  of the          government's case.  Arguments of this stripe do not trespass upon          the accused's  right to remain silent.   See Lockett v. Ohio, 438                                                   ___ _______    ____          U.S.  586,  595   (1978)  (finding  remarks  that   evidence  was          "unrefuted"  and  "uncontradicted"  not   to  violate  the  Fifth          Amendment); see also United States  v. Pitre, 960 F.2d 1112, 1124                      ___ ____ _____________     _____          (2d Cir. 1992)  (upholding a prosecutor's comment  that defendant          had offered no competing explanation); United States v. Castillo,                                                 _____________    ________          866 F.2d  1071, 1083 (9th  Cir. 1988)  (upholding a  prosecutor's          remark about  defendant's  failure  to  rebut  evidence);  United                                                                     ______          States  v.  Borchardt,  809  F.2d  1115,  1119  (5th  Cir.  1987)          ______      _________          (similar).   Within  the bounds  of  fair play  and due  process,          prosecutors are not barred from making powerful arguments.                    To be sure, it is  conceivable that a juror hearing the          prosecutors' words might have interpreted them as a commentary on                                          45          appellants' joint decision not to  testify.  But we cannot decide          this case  based on what amounts  to a doomsday scenario.   After          all,  an  appellate court  is  not at  liberty  to "infer  that a          prosecutor intends an ambiguous remark to have  its most damaging          meaning or that a jury, sitting through lengthy exhortation, will          draw   that  meaning   from  the   plethora   of  less   damaging          interpretations."  Lilly, 983 F.2d at 307 (citation omitted); see                             _____                                      ___          also  Robinson, 485  U.S. at  31 (explaining  "that an  appellate          ____  ________          court may [not] substitute its reading of ambiguous language  for          that of the trial court").  We are particularly unwilling to fish          in  the   pool  of  ambiguity   where  the  defendants   did  not          contemporaneously object or otherwise bring the  district court's          attention to  any potentially harmful  circumlocution during  the          summations.   Hence,  we  rule  that  the  prosecutors'  lack-of-          refutation references did not require a mistrial.                             B.  Inflammatory Statements.                             B.  Inflammatory Statements.                                 _______________________                    The  second  half  of   appellants'  challenge  to  the          government's   final   argument    implicates   what   appellants          characterize  as four  attempts to  inflame the  jury, viz.,  the                                                                 ____          prosecutors' suggestion that  the jury could consider  the effect          on the  community should  the Sepulveda  organization be able  to          continue  in   business;21  two   references  to   the  "war   on                                        ____________________               21The first prosecutor argued, inter alia:                                              _____ ____                    We  put this  organization  out of  business.                    And  it's up to  you to decide  that it stays                    that  way.    Because   ask  yourselves,  the                    business practices of this organization, this                    organized   group  of   drug  dealers,   what                                          46          drugs";22  and  a  monition  that  feelings  of  pity  should  be          subordinated to  the call of  civic duty.23   Because  defendants          failed  to object  to these  remarks  when they  were voiced,  we          review them only  for plain error.   See Smith, 982 F.2d  at 682.                                               ___ _____          Under that  regime, we  are constrained to  stay our  hand unless          improper remarks "so poisoned  the well that the  trial's outcome                                        ____________________                    practices will be allowed to  continue in the                    streets  of  Manchester and  the  surrounding                    towns  of New Hampshire  if these  people are                    allowed or permitted to  revive the drug ring                    . . . .               22In rebuttal argument, the second prosecutor stated:                    It's  a sad but true fact of law enforcement,                    particularly  of this war  on drugs,  that if                    you're  going to try to clean out the sewers,                    you've  got to roll  up your sleeves  and get                    down  in  with  the filth,  and,  ladies  and                    gentlemen,  I, for one, am proud to have gone                    down  into those sewers and I'm proud to have                    been part  of this  prosecution team and  I'm                    proud  to be  a  small part  of  this war  on                    drugs.               23In rebuttal, the second prosecutor also suggested:                    [I]f perhaps you  do feel  sorry for  anyone,                    then  what I'm asking  you to do,  ladies and                    gentlemen, is  to override any  such feelings                    with  your sense of duty as jurors, with your                    sense of responsibility as citizens, and with                    your  desire to do the job you've sworn to do                    in this  court of  law.   And consider  this.                    During this testimony Kurt Coriaty said  that                    if he  had not  been indicted and  prosecuted                    for his drug dealings, that he would still be                    on  the street today  selling drugs.   So ask                    yourselves, ladies and gentlemen, if you fail                    to  do your  duty  as  jurors  and  find  any                    defendant not  guilty just  because you  feel                    sorry for him, are you doing your community a                    service?   Are  you  doing  your  families  a                    service?    And  are  you  really doing  that                    defendant a service?                                          47          was likely  affected."  United  States v. Mejia-Lozano,  829 F.2d                                  ______________    ____________          268, 274 (1st Cir. 1987); accord United States v. Mateos-Sanchez,                                    ______ _____________    ______________          864  F.2d  232, 240-41  (1st  Cir. 1988).    None  of the  quoted          statements comprise plain error in the setting of this trial.                    1.   Protection of the Community.  The first statement,                    1.   Protection of the Community.                         ___________________________          see supra note 21, went too far:  prosecutors overreach when they          ___ _____          ask jurors to function as de facto vigilantes.  Yet, importantly,                                    __ _____          cf. United States v. Lester, 749 F.2d 1288, 1301 (9th Cir. 1984),          ___ _____________    ______          there  is  no  sign  that  the  buzznacking  about  the Sepulveda          organization resuming operations, while gratuitous, was part of a          pattern of  remarks specifically  intended to  inflame the  jury.          The  reference was  not prominently  featured  in the  summation;          rather,  it was prefatory,  serving to introduce  a recitation of          evidence that had  been presented at the trial.  When, as in this          case, the evidence of defendants' guilt  is strong, courts should          be very reluctant to find plain error in misguided rhetoric.  See                                                                        ___          United States v. Santana-Camacho, 833  F.2d 371, 373-74 (1st Cir.          _____________    _______________          1987); Mejia-Lozano, 829  F.2d at 274;  United States v.  Capone,                 ____________                     _____________     ______          683 F.2d 582, 586-87 (1st Cir.  1982).  So here:  we think  it is          wildly improbable, given the weight of the evidence, that what we          read   as  an  isolated,   relatively  subdued  appeal   for  law          enforcement  affected  the  trial's outcome.    Consequently, the          resumption-of-business  remarks  do  not   furnish  a  basis  for          reversal.   See United  States v. Smith,  918 F.2d  1551, 1562-63                      ___ ______________    _____          (11th Cir.  1990); Hernandez, 891  F.2d at 527; United  States v.                             _________                    ______________          Monaghan,  741  F.2d 1434,  1441  n.30  (D.C. Cir.  1984),  cert.          ________                                                    _____                                          48          denied, 470 U.S. 1085 (1985).          ______                    2.   The War  on Drugs.   A  somewhat different  set of                    2.   The War  on Drugs.                         _________________          considerations informs  our analysis  of the  next two  passages.          Defense attorneys introduced the phrase  "war on drugs" and  used          it  repeatedly during their opening statements and, later, during          their  summations.   Mindful  of the  environment created  by the          defense,  we  cannot  say  that  the  government's  two  rebuttal          references to an ongoing war on drugs, though better left unsaid,          comprised plain error.  The ancient adage applies:  what is sauce          for the  government's goose often may  prove to be sauce  for the          defendants' gander.                    Although we  deplore frank  appeals to  passion of  the          sort  typified by "war  on drugs"  rhetoric, see,  e.g., Arrieta-                                                       ___   ____  ________          Agressot, 3 F.3d at 527, we regard it as settled  that references          ________          to law enforcement efforts are not forbidden in summation if such          references are  incited  or invited  by,  or fairly  respond  to,          defendants' closing  statements.  See,  e.g., Smith, 918  F.2d at                                            ___   ____  _____          1563; United States v.  Brown, 887 F.2d 537, 542 (5th Cir. 1989);                _____________     _____          Machor,  879 F.2d at  956;   United States  v. Bascaro,  742 F.2d          ______                       _____________     _______          1335,  1353-54 (11th  Cir.  1984), cert.  denied,  472 U.S.  1017                                             _____  ______          (1985).  Though  there may well be exceptions to  this rule,24 no          such exceptions  lie for cases  like this one    cases  where the          dysphemisms are  few in number, do not escalate the level of fire                                        ____________________               24We  have, for instance, warned prosecutors that "there are          limits  to the  extent that  we  will permit  fighting fire  with          fire."   Mejia-Lozano, 829 F.2d at 274.  Merely because a defense                   ____________          attorney opens the  door does not mean that a prosecutor can come          storming through it in a pair of hobnailed boots.                                          49          and  brimstone that characterized  the defense's oratory,  and do          not provoke  a contemporaneous objection.   See United  States v.                                                      ___ ______________          Tajeddini, 996 F.2d 1278, 1285 (1st Cir. 1993); Mejia-Lozano, 829          _________                                       ____________          F.2d at 274.                    3.    Discouraging  Sympathy.    For  somewhat  similar                    3.    Discouraging  Sympathy.                          ______________________          reasons, we  find the  final challenged  statement, quoted  supra                                                                      _____          note  23,  to fall  within the  pale.   Viewed  in  context, this          statement,  which questioned whether an acquittal out of sympathy          would  be in  the  community  interest, was  made  to dampen  the          defense's  flirtation with  jury  nullification (described  infra                                                                      _____          Part VIII).   Courts should  allow prosecutors greater  leeway in          rebuttal  when the defense has  itself breached the standards for          proper summation.   See  Young, 470  U.S. at  11; Lawn  v. United                              ___  _____                    ____     ______          States, 355 U.S. 339, 359  n.15 (1958); Mejia-Lozano, 829 F.2d at          ______                                  ____________          274;  United States  v. Flaherty,  668  F.2d 566,  598 (1st  Cir.                _____________     ________          1981).  Applying this offshoot of the goose-and-gander principle,          we  hold that  the challenged  comment did  not constitute  plain          error.          VIII.  JURY NULLIFICATION          VIII.  JURY NULLIFICATION                    The   defendants   invoked   the   specter   of    jury          nullification  during  final  arguments.    Labrie's  lawyer,  in          particular, invited the jury to "send out  a question" concerning          this doctrine.  Three non-events followed; the government did not          object to this  soliloquy, the district  court did not  intervene          sua sponte,  and the court's  charge did not broach  the subject.          ___ ______          Nevertheless, the deliberating jury took the invitation literally                                          50          and asked the judge to "[c]larify the law on jury nullification."          The court responded by telling the jury:                    Federal   trial  judges   are  forbidden   to                    instruct on jury  nullification, because they                    are  required  to instruct  only  on  the law                    which applies to a case.  As I have indicated                    to  you, the burden in each instance which is                    here placed  upon the Government is  to prove                    each element of the  offenses . . .  beyond a                    reasonable  doubt,  and  in  the  event   the                    Government  fails to  sustain  its burden  of                    proof  beyond  a reasonable  doubt as  to any                    essential  element  of  any  offense  charged                    against each defendant, it has then failed in                    its  burden of proof as to such defendant and                    that defendant is to be acquitted.  In short,                    if the Government proves its case against any                    defendant, you should convict that defendant.                    If it  fails to  prove its  case against  any                    defendant you must acquit that defendant.          Appellants objected to  this supplemental instruction.   They now          argue that the instruction amounted to a wrongful repudiation  of          the time-honored concept of jury nullification.                    The  applicable rule is  that, although  jurors possess          the  raw power to set  an accused free  for any reason  or for no          reason, their duty is  to apply the law as  given to them by  the          court.  See   United States v.  Boardman, 419 F.2d 110,  116 (1st                  ___   _____________     ________          Cir.  1969),  cert. denied,  397 U.S.  991 (1970).   Accordingly,                        _____ ______          while jurors may choose to  flex their muscles, ignoring both law          and evidence in  a gadarene rush to acquit  a criminal defendant,          neither the court nor counsel should encourage jurors to exercise          this power.   See United  States v. Trujillo,  714 F.2d 102,  106                        ___ ______________    ________          (11th Cir.  1983).  A  trial judge, therefore, may  block defense          attorneys' attempts  to serenade  a jury with  the siren  song of          nullification,  see United States  v. Garcia-Rosa, 876  F.2d 209,                          ___ _____________     ___________                                          51          226 (1st  Cir. 1989); and, indeed,  may instruct the  jury on the          dimensions of their duty to the exclusion of  jury nullification,          see Trujillo, 714 F.2d at 105-06 (collecting cases).          ___ ________                    To the extent that appellants, during closing argument,          managed to  mention nullification,  they received  more than  was          their  due.    Having  pocketed  this  gratuity,  appellants  now          complain that they were  not allowed to capitalize  on it.   When          the jurors rose to the  bait, appellants say, Judge Devine should          have   assured  them   that  nullification   is  an   "historical          prerogative"  of juries  from  time  immemorial.    We  disagree.          Though jury nullification has a long and sometimes  storied past,          see Boardman, 419  F.2d at 116, the  case law makes plain  that a          ___ ________          judge may not  instruct the jury anent its  history, vitality, or          use.  See,  e.g., United States  v. Desmarais, 938 F.2d  347, 350                ___   ____  _____________     _________          (1st  Cir.  1991)  (collecting  cases).    This  proscription  is          invariant; it makes no difference that the jury inquired, or that          an  aggressive  lawyer  managed  to  pique  a  particular  jury's          curiosity by mentioning the subject in closing argument, or  that          a napping prosecutor  failed to raise a timely  objection to that          allusion.    Thus,  the  district  court  appropriately  scotched          appellants' suggested jury instruction.                    Appellants'  fallback  position     that  the  district          court, if  disinclined to sing the praises of jury nullification,          should have  refrained from  giving any  supplemental instruction          and,  instead, should have  stonewalled   is  not well conceived.          The objection  focuses on  the district  court's opening  comment                                          52          that "[f]ederal  trial judges are  forbidden to instruct  on jury          nullification,"  interpreting  this  as  a  judicial  prohibition          against  the jury's  use of  its inherent  power.   The objection          fails for  several reasons,  most noticeably  because the  quoted          statement conveys no such chilling effect.                    Taken  literally, the  judge's  comment is  an accurate          recitation of the law and  an appropriate rejoinder to the jury's          question on  nullification (a question that appellants prompted).          The district court  explained why it could not  answer the jury's          request for more information on nullification.  The court went on          to  repeat its earlier instruction that  if the government proved          its  case  the jury  "should"  convict, while  if  the government          failed to carry its burden the jury "must" acquit.  This contrast          in directives, together with  the court's refusal to instruct  in          any  detail  about  the  doctrine  of  jury  nullification,  left          pregnant the possibility that the jury could ignore the law if it          so chose.  Whether the jury perceived this possibility or not, no          error infiltrated the court's supplemental instruction.          IX.  VARIANCE BETWEEN INDICTMENT AND PROOF          IX.  VARIANCE BETWEEN INDICTMENT AND PROOF                    Appellants Edgar Sepulveda and Tony Rood now claim that          the  district court should have  acquitted them because they were          not part  of the charged  conspiracy.  We review  their claims to          determine whether  there is  sufficient evidence  to support  the          jury's verdict.  See David, 940 F.2d at 732.  We conclude that  a                           ___ _____          rational  jury  could find,  as  this  jury  did, that  a  single          conspiracy  existed, and that  the two objectors  participated in                                          53          it.                    We start with bedrock.  Ordinarily, questions anent the          number  and structure  of conspiracies  present  matters of  fact          suitable for  resolution by  a jury.   See id.; United  States v.                                                 ___ ___  ______________          Boylan, 898 F.2d 230, 243 (1st Cir.),  cert. denied, 489 U.S. 849          ______                                 _____ ______          (1990).   Of  course, the  jury's  inquiry is  guided by  certain          principles.   For  example, in  a  unitary conspiracy  it is  not          necessary that the membership remain static, see United States v.                                                       ___ _____________          Perholtz, 842 F.2d  343, 364 (D.C. Cir.), cert.  denied, 488 U.S.          ________                                  _____  ______          821 (1988), or that all members join at the same time, see United                                                                 ___ ______          States v.  Cintolo, 818  F.2d 980, 997  (1st Cir.)  (deeming that          ______     _______          latecomers to a  conspiracy adopt the prior acts and declarations          of earlier arrivals), cert. denied,  484 U.S. 913 (1987), or that                                _____ ______          a given member knows  all his fellow coconspirators, see  Rivera-                                                               ___  _______          Santiago, 872 F.2d at 1079.   Similarly, the modus operandi of  a          ________                                     _____ ________          conspiracy may vary over time without negating the existence of a          single conspiracy.  See Garcia-Rosa, 876 F.2d at 223.                              ___ ___________                    Turning to the instant case,  several defendants argued          that  they were  not  members  of the  charged  conspiracy.   The          district  court instructed  the  jury that  it  should convict  a          particular defendant only  if it found him  or her to be  part of          the  single  conspiracy  limned  in the  indictment.    The court          cautioned the  jurors that  they must  acquit  any defendant  not          linked  to  that  conspiracy even  if  they  concluded that  such          defendant  had  been a  member  of  a  separate, equally  heinous          conspiracy.  The  verdict, then, had the effect  of rejecting the                                          54          "multiple  conspiracy"  defense,  instead signifying  the  jury's          contrary conclusion that the appellants collogued together within          the framework of the master conspiracy.                    To  be sure,  the  charged  conspiracy  had  a  protean          quality    but  many criminal  conspiracies,  particularly  large          conspiracies that  function for  extended periods  of time,  must          adjust  to  cope with  changing  conditions.    In this  respect,          conspiracies are like other business organizations:  a conspiracy          may  hire,  fire,  retool, change  suppliers,  expand,  downsize,          refine   its  operating   practices,   undertake  new   marketing          strategies, or  shift its priorities  from time  to time  without          sacrificing its essential  identity.  It is, therefore, not fatal          to  the  government's  "single  conspiracy"  theory  that   David          Sepulveda began his career  by patronizing a cocaine supplier  in          Nashua, and  later switched to  a source in Lawrence.   Likewise,          the fact that the organization's methods and tactics evolved over          time did not dictate  a finding of  two, three, or four  separate          conspiracies.    The government  offered  evidence  showing that,          throughout the  six-year period  covered by  the indictment,  the          goals  of the organization were constant,  its leadership did not          change, and  much of its  membership remained stable.   These are          important indicia  of unitariness.   See David, 940 F.2d  at 734.                                               ___ _____          All in all,  we find the common threads adequate to create a jury          question as to whether a single conspiracy existed.                    The  evidence  tying  Edgar  Sepulveda  to  the  single          conspiracy  is more  than ample.   Two  witnesses testified  that                                          55          Edgar, himself, sold them cocaine.  Four witnesses testified that          Edgar routinely  accompanied his  brother, David,  on drug-buying          sprees.   One of  these witnesses,  Norberto Perez, testified  to          taking  an average  of one  such trip  a week with  the Sepulveda          siblings over a protracted period of time.  Another witness, John          Rice, testified that he  saw the Sepulvedas packaging  cocaine at          Driesse's home.                    There is  similar, albeit  less pervasive, evidence  of          Rood's role  in the  organization.  Perez  testified that  he and          Rood made  over fifteen trips  to Lawrence in order  to replenish          David  Sepulveda's drug  inventory.   When  David  agreed to  pay          Santos in  kind for chauffeuring  him during a drug  delivery, he          instructed  Rood,  in  Santos's  presence,  to  give  Santos  his          stipend.   On  another occasion,  David  sent Rood  and Perez  to          retrieve cocaine that had  been abandoned during a  police chase.          Finally,  a gaggle of witnesses, including Santos, testified that          they had purchased cocaine from Rood.  From this variegated proof          the jury could permissibly weave a tapestry linking Rood with the          master conspiracy rather  than isolating him within  the cloister          of the self-styled "mini-conspiracy" in which he now professes to          have been involved.  See Moran, 984 F.2d at 1304; Glenn, 828 F.2d                               ___ _____                    _____          at 861-62.                    To recapitulate,  the record satisfactorily  supports a          multifaceted  finding that the  single conspiracy charged  in the          indictment  existed and that  both Edgar Sepulveda  and Tony Rood          enlisted  in it.   Thus,  no  material variance  existed and  the                                          56          district court properly refused to order acquittal.          X.  POTPOURRI          X.  POTPOURRI                    Appellants raise a  number of other issues.   Believing          that  exegetic treatment of  these points  would serve  no useful          purpose, we  reject some  by means of  this global  reference and          discuss the rest in summary fashion.                         A.  Particularity of the Indictment.                         A.  Particularity of the Indictment.                             _______________________________                    Two  appellants  challenge  the  particularity  of  the          indictment as it applies to them.  While we comment separately on          each  challenge, we  first lay  out  the black-letter  rule:   in          general,  an  indictment   is  sufficiently   particular  if   it          elucidates  the elements of the  crime, enlightens a defendant as          to the  nature of the charge  against which she must  defend, and          enables  her   to  plead  double   jeopardy  in  bar   of  future          prosecutions for the same offense.  See Hamling v. United States,                                              ___ _______    _____________          418  U.S. 87,  117 (1974)  (collecting cases);  see also  Fed. R.                                                          ___ ____          Crim. P. 7(c)(1).                    1.  Arline Welch.  Defendant Arline Welch argues  that,                    1.  Arline Welch.                        ____________          as it  applies to  her, the  indictment transgresses  the Hamling                                                                    _______          guidelines.  The gravamen of her complaint is that the indictment          neither contains the elements of  the crime charged nor limns the          date, time,  and place of  her ostensible criminal activity.   We          think  her reading  of the  charging papers  is colored  by self-          interest.                    The grand jury indicted Welch for conspiracy to possess          and distribute  cocaine in  violation of  21 U.S.C.     846.   To                                          57          convict  her, therefore,  the  government had  to  show beyond  a          reasonable doubt that a drug-trafficking conspiracy existed about          which Welch knew and in  which she voluntarily participated.  See                                                                        ___          David, 940 F.2d at 735 (explaining elements of conspiracy under            _____          846);  Gomez-Pabon, 911  F.2d at  852 (similar).   The indictment                 ___________          specifies the  law which  Welch is alleged  to have  violated and          elaborates that she, with others, "knowingly" and "intentionally"          agreed to act in contravention of that law.   The indictment also          provides a temporal framework, asserts that Welch's residence was          used as  a packaging center  for the drug distribution  ring, and          states that she worked as a "runner" and a "street-level dealer."          We think  this information  sufficiently spelled  out the  crime,          apprised Welch of the charge against which she had to defend, and          protected her from the boggart  of double jeopardy.  See Hamling,                                                               ___ _______          418 U.S. at 117;  Paiva, 892 F.2d at 154.  In  the last analysis,                            _____          indictments need not be infinitely specific.                    2.   Kevin Cullinane.   Defendant Kevin  Cullinane also                    2.   Kevin Cullinane.                         _______________          challenges the indictment's  particularity.  Notwithstanding  the          pervasive proof of his complicitous conduct adduced at trial, see                                                                        ___          supra Part II(B), Cullinane points out that the indictment itself          _____          only mentions him twice, asserting that he purchased cocaine from          David   Sepulveda  and  that,   on  one  specific   occasion,  he          distributed  cocaine to another coconspirator.  But the frequency          with which a person is (or is  not) mentioned in an indictment is          an  insufficient  indicium  of  the  indictment's  particularity.          Here,  the  charging  papers  contained  considerable  contextual                                          58          detail.   Given  the  indictment's  general  description  of  the          conspiracy and  identification of the alleged  coconspirators, we          find  that  it   put  Cullinane  on  fair  notice  and  contained          information sufficient to allow him  to prepare his defense.  See                                                                        ___          Hamling, 418 U.S. at 117.  The drug conspiracy statute, 21 U.S.C.          _______            846,  does not  require the government  to plead  or prove  any          particular overt  acts in  furtherance of  a charged  conspiracy.          See United  States v. O'Campo,  973 F.2d 1015, 1019-20  (1st Cir.          ___ ______________    _______          1992); Paiva, 892 F.2d at 155.                 _____                               B.  Bill of Particulars.                               B.  Bill of Particulars.                                   ___________________                    The  same  two  appellants assign  error  to  the lower          court's  denial  of  their  motions  for  bills  of  particulars.          Motions  for bills of  particulars are seldom  employed in modern          federal practice. When pursued, they  need be granted only if the          accused, in the absence of a more detailed specification, will be          disabled from preparing  a defense, caught by unfair  surprise at          trial, or hampered in seeking  the shelter of the Double Jeopardy          Clause.  See  United States  v. Abreu, 952  F.2d 1458, 1469  (1st                   ___  _____________     _____          Cir.) (collecting cases),  cert. denied, 112 S.  Ct. 1695 (1992).                                     _____ ______          We  review refusals  to  require such  bills  under an  abuse-of-          discretion test.   See United States v. Hallock, 941  F.2d 36, 40                             ___ _____________    _______          (1st Cir. 1991).                    Here, both appellants enjoyed  the benefits of modified          open-file discovery, i.e.,  automatic discovery that  encompassed                               ____          all relevant data except Jencks Act material related to witnesses          not  employed in law enforcement.  Neither appellant convincingly                                          59          relates  a concrete instance  of inability to  prepare, untenable          surprise, or other  cognizable prejudice stemming from  the trial          court's refusal to mandate further particulars.  For our part, we          have  been  unable  to  discover  any  such  instance.    In  the          unremarkable circumstances of this case, the district court acted          well  within  the   encincture  of  its  discretion   in  denying          appellants' motions.                                  C.  Speedy Trial.                                  C.  Speedy Trial.                                      ____________                    Arline Welch  contends that  the court  below erred  in          refusing to  dismiss the charges  against her on the  ground that          too long  a time  intervened between indictment  and trial.   Her          claim invokes  the  Speedy  Trial Act,  18  U.S.C.      3161-3174          (1988).  The Act provides in pertinent part:                         In  any  case  in which  a  plea  of not                    guilty is entered,  the trial of a  defendant                    charged in  an . .  . indictment . .  . shall                    commence within seventy days from the  filing                    date . . .  of the . . . indictment,  or from                    the date the defendant has appeared before  a                    judicial officer  . . ., whichever  date last                    occurs.          18 U.S.C.   3161(c)(1).                    For   Speedy  Trial   Act  purposes,   time  has   both          quantitative  and qualitative dimensions.  The Act's 70-day trial          mandate,  see id.,  exemplifies its  quantitative side.   On  the                    ___ ___          qualitative  side,  the  Act  excludes  from  the  70-day  period          intervals of delay  that result from such events  as the pendency          of pretrial motions, see 18 U.S.C.   3161(h)(1)(F),  the presence                               ___          of other defendants  in the case "as  to whom the time  for trial          has not run and no motion for severance has been granted," id. at                                                                     ___                                          60            3161(h)(7), or continuances which  serve the "ends of justice,"          id. at   3161(h)(8)(A).  Therefore, a violation of the Act occurs          ___          only if (i) a sufficient  number of days elapse (the quantitative          benchmark),  and (ii) the days are nonexcludable (the qualitative          benchmark).                    Against this background, the chronology of Welch's case          is telling.  Her arraignment took place on November 19, 1990, and          her trial started on April 2, 1991.  Quantitatively, this 134-day          interval  exceeds the  goal set  by the Speedy  Trial Act.   But,          qualitatively,  the  record  presents   a  much  more  excusatory          picture.   The bulk of  the time elapsed between  arraignment and          trial  is  excludable  for  Speedy  Trial  Act  purposes  because          pretrial motions filed by the defendants, as  a group, engendered          considerable delay (bringing the nonexcludable time to fewer than          35 days).   Hence, the court  below did not  err in declining  to          dismiss  the case  under  the  Speedy Trial  Act.25   See,  e.g.,                                                                ___   ____          United  States  v. Ramirez,  973  F.2d  36,  37 (1st  Cir.  1992)          ______________     _______          (collecting cases); United States v. Torres Lopez, 851 F.2d  520,                              _____________    ____________          526 (1st Cir.  1988), cert. denied, 489 U.S.  1021 (1989); United                                _____ ______                         ______          States v. Anello, 765 F.2d  253, 256-58 (1st Cir.), cert. denied,          ______    ______                                    _____ ______          474 U.S. 996 (1985).                             D.  David Chase's Testimony.                             D.  David Chase's Testimony.                                 _______________________                    At  trial,  David  Chase testified  that  he  regularly                                        ____________________               25We  note that the district court  also granted an ends-of-          justice  continuance on December  18, 1990, in  response to David          Sepulveda's  motion for  an  extension  of  discovery  deadlines,          thereby providing an  additional source of excludable  time.  See                                                                        ___          18 U.S.C.   3161(h)(8)(A).                                          61          purchased cocaine  from appellant  Cullinane until, having  grown          dissatisfied  with the  quality of  Cullinane's  wares, he  began          buying  directly from David  Sepulveda.  Cullinane  argues before          us, as he  argued below, that Chase's testimony  should have been          purged   because  Chase  did  not  explicitly  tie  Cullinane  to          Sepulveda.  We disagree.                      The  relevancy  of a  witness's  testimony cannot  be          gauged in isolation.  See United States v. Hickey, 596 F.2d 1082,                                ___ _____________    ______          1089  (1st Cir.),  cert. denied,  444 U.S.  853 (1979).   Several                             _____ ______          witnesses other  than Chase  described Cullinane's  dealings with          Sepulveda,  including his purchases of contraband and their joint          participation  in drug-buying excursions.   Given this contextual          detail, the  jury could well infer  that the sales to  Chase were          connected to the Cullinane-Sepulveda  axis.  In a criminal  case,          proof  need  not  be  explicit;  juries  are  permitted,  indeed,          encouraged, to draw  reasonable inferences from the  facts before          them.  See, e.g.,  Echeverri, 982 F.2d  at 679; United States  v.                 ___  ____   _________                    _____________          Ingraham, 832 F.2d 229, 239-40 (1st Cir. 1987), cert. denied, 486          ________                                        _____ ______          U.S.  1009  (1988).    The  district  court  did  not  abuse  its          discretion in admitting evidence of Cullinane's sales to Chase as          circumstantial evidence of  Cullinane's role in  the distribution          network.                           E.  Steven Ranfros's Testimony.                           E.  Steven Ranfros's Testimony.                               __________________________                    David  Sepulveda objected  to the  testimony of  Steven          Ranfros,  a police  officer  who  recounted  that  Sepulveda  and          several of his associates chased Ranfros when they discovered him                                          62          watching  them  from  a  wooded area.    Sepulveda  insists  that          Ranfros's testimony lacks any relevance.                    Relevance is defined  in terms of probative  value, see                                                                        ___          Fed. R. Evid. 401, and  trial courts are afforded wide discretion          in  assessing  the  relevance and  probative  value  of proffered          evidence.  See United States v. Sutton, 970 F.2d 1001, 1006  (1st                     ___ _____________    ______          Cir.  1992); United  States v.  Nickens, 955  F.2d 112,  125 (1st                       ______________     _______          Cir.), cert. denied, 113 S. Ct.  108 (1992).  We will disturb  an                 _____ ______          exercise  of  that discretion  only  upon a  showing  of manifest          abuse.  See United States v. Yefsky, 994 F.2d 885, 898  (1st Cir.                  ___ _____________    ______          1993).   We discern  no such problem  here.   Ranfros's testimony          could  be taken  to  bear  on guilty  knowledge,  and, thus,  the          district court had discretion to allow the jury to consider it.                                 F.  The Terry Stop.                                 F.  The Terry Stop.                                     ______________                    At trial, the government  introduced evidence that  the          police  seized $4,200 from  David Sepulveda after  a highway stop          near  Nashua.   Sepulveda moved  to suppress  the evidence.   The          government contended that  the cash constituted  the fruits of  a          search incident  to a lawful  arrest.  The district  court denied          the  suppression motion without comment.  Sepulveda assigns error          to this  ruling and to  the admission of evidence  emanating from          the seizure.                    In  its appellate  brief, the  government concedes  the          fallibility of the construct that it hawked in the district court          and, instead, attempts to justify the search under Terry v. Ohio,                                                             _____    ____          392  U.S. 1,  29-30  (1968).   At  oral  argument the  government                                          63          executed yet  another about-face,  acknowledging that the  Terry-                                                                     _____          based yarn  spun in its  brief is easily  unravelled.  We  do not          find  it surprising  that  the  prosecution,  like  a  Pirandello          character in  search of  an author,  has encountered  insuperable          difficulties in articulating a viable theory:  the short of it is          that the cash  was unlawfully  seized and  that evidence  derived          from  the  seizure  should  have  been suppressed.    We  do  not          understand why  the government is  unwilling simply to  face that          fact    or why it pressed so vigorously to have evidence obtained          in a patently illegal manner admitted in the first place.                    At  any rate,  the matter  is academic.   As  a general          rule,  a defendant  is not  shielded if  the  government violates          someone  else's  constitutional  rights.   See  United  States v.                                                     ___  ______________          Santana, 6 F.3d 1, 8  (1st Cir. 1993).  Consequently, Sepulveda's          _______          coconspirators have no standing to raise  a claimed abridgment of          his Fourth Amendment  rights.  See United States  v. Padilla, 113                                         ___ _____________     _______          S. Ct. 1936, 1939 (1993); Rawlings v. Kentucky, 448 U.S. 98,  106                                    ________    ________          (1980).                    As  to  Sepulveda  himself,  the  erroneously  admitted          evidence is cumulative.   In testimony not covered  by the motion          to suppress, a civilian witness, Michael Lacerte, related that he          had given  the funds in  question to Sepulveda so  that Sepulveda          could   buy  cocaine.     Lacerte   also  recounted   Sepulveda's          explanation as to seizure of the money.  Under the circumstances,          and bearing in mind the factors that frame our inquiry, see supra                                                                  ___ _____          pp. 30,  whatever error inhered  in admitting evidence  anent the                                          64          seizure and its sequelae was entirely harmless.                                   G.  Jury Taint.                                   G.  Jury Taint.                                       __________                    At one point during the  trial, a juror joked about one          of the defendants.  The  district court proceeded to question two          jurors  out of  earshot of  the  venire.   After identifying  the          individual  responsible for  the  wisecrack, the  court dismissed          her.   Appellants  moved unsuccessfully  for  a mistrial  and now          posit error based on the denial of their motion.                    We  find  nothing  amiss.   When  a  potentially taint-          producing  event threatens  to  mar  the  jury's  integrity,  the          district  court has fairly  broad discretion in  deciding whether          the  situation is  susceptible to  remediation, and  if  so, what          corrective action might be appropriate.   See Boylan, 898 F.2d at                                                    ___ ______          258; Gutierrez-Rodriguez  v. Cartagena,  882 F.2d  553, 570  (1st               ___________________     _________          Cir. 1989).   Unless the event leaves  so sour a taste  that less          extreme palliatives will prove inadequate to undo serious damage,          the  mere  possibility  of  jury taint  does  not  necessitate  a          mistrial.  See  United States v. Hunnewell, 891  F.2d 955, 960-61                     ___  _____________    _________          (1st Cir. 1989).  Mindful of the trial  court's superior coign of          vantage, we  accord great respect  to a district  judge's finding          that a  jury has not been  irreparably tainted.  See  Boylan, 898                                                           ___  ______          F.2d at 258.                    Here,   the    judge   employed   a    combination   of          amelioratives:  he removed the  offending juror from the case and          issued hortatory  instructions to  the remaining  jurors.   Given          what  transpired, the judge's  prescription seems reasonably well                                          65          calculated  to  protect  the defendants'  legitimate  rights; the          joke,  albeit tasteless,  did not  work a  per se  deprivation of                                                     ___ __          appellants' right to a fair trial.  Consequently, the court acted          appropriately in refusing to abort the trial.  See Hunnewell, 891                                                         ___ _________          F.2d at 961.                             H.  Destruction of Evidence.                             H.  Destruction of Evidence.                                 _______________________                    On   May  5,  1989,   in  the  course   of  a  separate          investigation, the government took  custody of certain  telephone          records  belonging to defendant  Cullinane.  After  examining the          records, the  government returned them to  Cullinane's housemate.          In  turn,  the  housemate  threw  them  out.    Seizing  on  this          development,  appellant  Arline  Welch   asseverates  that  those          records  may have  contained  exculpatory material  vis-a-vis her          relationship with Cullinane and that, therefore, the government's          failure  to maintain them  requires dismissal of  the indictment.          The asseveration is full of holes.                    Government  destruction   of  potentially   exculpatory          evidence only violates the rule in Brady,  373 U.S. at 87, if the                                             _____          evidence  possesses apparent exculpatory  value that cannot fully          be  replicated through other sources, and  if the government acts          willfully or in bad faith in failing to preserve it.  See Arizona                                                                ___ _______          v. Youngblood, 488 U.S. 51,  58 (1988); California v.  Trombetta,             __________                           __________     _________          467 U.S.  479, 488-89  (1984); United States  v. Femia,  ___ F.3d                                         _____________     _____          ___,  ___  (1st  Cir.  1993)  [No. 93-1276,  slip  op.  at  8-9].          Government investigators typically cast a  wide net and haul in a          variety  of  items.    While evidence,  once  seized,  cannot  be                                          66          destroyed  willy-nilly, the government does not become an insurer          of  the  perpetual  availability  of  every  item  caught in  its          investigatory net.  See, e.g., United States v. Kincaid, 712 F.2d                              ___  ____  _____________    _______          1, 2-3 (1st Cir. 1983).                    In  the situation  at  hand,  the  government  did  not          destroy  the  records Welch  seeks  but merely  returned  them to          Cullinane's residence.   There  is no  hint of  bad faith and  no          indication that the agents knew, or should have anticipated, that          Cullinane's friend  would thereafter discard them.   Accordingly,          Welch's motion is best regarded as a throwaway.26                                I.  Cumulative Error.                                I.  Cumulative Error.                                    ________________                    Appellants argue  that  even if  certain trial  errors,          taken in isolation,  appear harmless, the accumulation  of errors          effectively undermines due process and demands a fresh start.  We          accept   the   theoretical   underpinnings   of  this   argument.          Individual errors,  insufficient in  themselves to  necessitate a          new trial, may in the  aggregate have a more debilitating effect.          See, e.g.,  United States  v. Dwyer,  843 F.2d  60, 65 (1st  Cir.          ___  ____   _____________     _____          1988); Dunn v. Perrin, 570 F.2d 21, 25  (1st Cir.), cert. denied,                 ____    ______                               _____ ______          437  U.S. 910 (1978); cf. United States v. Samango, 607 F.2d 877,                                ___ _____________    _______          884  (9th  Cir.  1979) (employing  cumulative  error  doctrine to          invalidate results of grand jury  proceeding).  In other words, a          column  of  errors  may  sometimes  have  a  logarithmic  effect,          producing a total  impact greater than the arithmetic  sum of its                                        ____________________               26In view of  this shortfall, we need not  address the other          prongs of the test.                                          67          constituent parts.                    Of  necessity,   claims  under  the   cumulative  error          doctrine are  sui generis.   A  reviewing tribunal must  consider                        ___ _______          each such claim  against the background of  the case as  a whole,          paying particular weight to factors such as the nature and number          of the  errors committed;  their interrelationship,  if any,  and          combined effect; how the district  court dealt with the errors as          they arose (including the efficacy   or lack of efficacy   of any          remedial efforts);  and the  strength of  the government's  case.          See,  e.g., Mejia-Lozano, 829  F.2d at 274  n.4.  The  run of the          ___   ____  ____________          trial  may   also  be  important;   a  handful  of   miscues,  in          combination, may often pack a greater punch in a short trial than          in a much longer trial.                    The  cumulative  error  doctrine  is  inapposite  here.          While we have  uncovered a few benign bevues,  e.g., the district                                                         ____          court's failure  to grant  David Sepulveda's  motion to  suppress          evidence of money illegally seized from him, see supra Part X(F),                                                       ___ _____          and  the ill-advised admission  of two statements  unsupported by          extrinsic  evidence and, hence,  ineligible for special swaddling          under Fed. R. Evid. 801(d)(2)(E), see supra Part V(B), the errors                                            ___ _____          were  not  portentous;  they  were  few  and  far  between;  they          possessed  no  special  symbiotic effect;  they  occurred  in the          course of a  two-month trial; and the government's  case was very          strong.  Consequently, the errors,  in the aggregate, do not come          close to achieving  the critical mass necessary to  cast a shadow          upon the integrity of the verdict.                                          68                    Considering the  trial's length, complexity,  and hard-          fought nature,  the district court's  handling of  it evokes  our          admiration.    Appellants'  focus on  cumulative  error  does not          change  the  picture.    The  Constitution  entitles  a  criminal          defendant to a  fair trial,  not to  a mistake-free  trial.   See                                                                        ___          Delaware v. Van Arsdall, 475  U.S. 673, 681 (1986); United States          ________    ___________                             _____________          v. Polito,  856 F.2d 414, 418 (1st Cir. 1988).   When all is said             ______          and done, the proceedings here meet this measure.          XI.  SENTENCING ISSUES          XI.  SENTENCING ISSUES                    The sentencing issues raised in these appeals implicate          the  federal sentencing  guidelines.27   See  David, 940  F.2d at                                                   ___  _____          739  (holding  that the  guidelines  apply to  a  conspiracy that          "begins before the guidelines' effective date and continues after          the  effective date").  Six appellants (Rood, Wallace, Cullinane,          Arline  Welch,  Edward  Welch,  and  Johnson)  challenge  rulings          relative to  the imposition  of sentence.28   To the  extent that          these challenges touch  upon the district court's  factfinding or          its evaluative judgments in applying the guidelines to the  facts          as found, appellate review is for clear error.  See United States                                                          ___ _____________                                        ____________________               27Since the  district court sentenced appellants  on various          dates  in  January   1992,  the  November  1991  version  of  the          sentencing guidelines applies in this case.  See United States v.                                                       ___ _____________          Harotunian, 920 F.2d 1040, 1041-42 (1st Cir.  1990) ("Barring any          __________          ex post facto problem, a defendant is to be punished according to          __ ____ _____          the   guidelines  in  effect   at  the  time   of  sentencing.").          Therefore, all references to the sentencing guidelines will be to          the  November   1991  edition,   unless  otherwise   specifically          indicated.               28The court  below sentenced  appellants to assorted  prison          terms  ranging from  a  high of  almost  twenty-two years  (David          Sepulveda) to a low of five years.                                          69          v. St.  Cyr, 977 F.2d 698,  701 (1st Cir.  1992).  To  the extent             ________          that  the challenges  raise  "pure" questions  of law  or require          interpretation of the guidelines, our review is plenary.  See id.                                                                    ___ ___                               A.  General Principles.                               A.  General Principles.                                   __________________                    In   drug-trafficking   cases  under   the   sentencing          guidelines, sentences  are largely quantity-driven.   See,  e.g.,                                                                ___   ____          United States v. Morillo,  ___ F.3d ___, ___ (1st Cir. 1993) [No.          _____________    _______          93-1388,  slip op. at  12 & n.10];  United States  v. Garcia, 954                                              _____________     ______          F.2d  12, 15 (1st Cir.  1992); United States  v. Blanco, 888 F.2d                                         _____________     ______          907, 909-11 (1st  Cir. 1989); see also United  States v. Bradley,                                        ___ ____ ______________    _______          917 F.2d 601, 604 (1st Cir. 1990) (describing drug quantity as "a          key  datum"  for   sentencing  purposes).    The   drug  quantity          attributable  to  a  particular defendant  is  derived  by adding          together the amounts of narcotics, actual or negotiated, bound up          in the acts  "that were  part of  the same course  of conduct  or          common scheme  or plan as  the offense of conviction."   U.S.S.G.           1B1.3(a)(2).   However,  in the  context  of jointly  undertaken          criminal  activity,  such as  a  conspiracy, a  defendant  is not          automatically  saddled with the  full weight of  the conspiracy's          wrongdoing;  rather,  a  defendant is  responsible  for  drugs he          personally  handled  or  anticipated  handling,  and,  under  the          relevant  conduct rubric, for  drugs involved in  additional acts          that  were reasonably  foreseeable by  him and were  committed in          furtherance  of the  conspiracy.   See  Garcia, 954  F.2d at  15;                                             ___  ______          David,  940 F.2d at 742; see also U.S.S.G.  1B1.3(a)(1), comment.          _____                    ___ ____          (n.1).  In this regard, we have emphasized that "the measure of a                                          70          defendant's  accountability for drug transactions in which he was          not personally  involved is usually  congruent with the  scope of          his  agreement  with  the  other  participants  in  the  criminal          enterprise."  Garcia, 954 F.2d at 16.                        ______                           B.  Tony Rood; William Wallace.                           B.  Tony Rood; William Wallace.                               __________________________                    Appellants  Rood and  Wallace  object to  the  district          court's  attribution  of  particular  drug  quantities  to  them.          Because the same type of error infects both sentences, we discuss          them in the ensemble.                    In regard  to Rood  and Wallace,  the district  court's          drug quantity calculations  rested essentially  on Perez's  trial          testimony.29    According  to  Perez,  Rood  accompanied  him  on          fifteen  to twenty drug-buying jaunts and Wallace accompanied him          on ten to  fifteen such trips.   Perez did not  assign particular          amounts to particular  people on  particular trips.   Rather,  he          testified  in sweeping  generalities, stating  that the  smallest          amount he  remembered having been  acquired, in the eighty  or so          trips he took with Sepulveda and an assortment of companions over          a two-year period (1987-1989), was four ounces (113.4 grams), and          the largest amount acquired was one kilogram (an amount purchased          more  than once).   In  preparing  the presentence  investigation          report  (PSI Report), the probation department adopted methods of          calculation  apparently  urged  by the  prosecution.    The basic                                        ____________________               29To  be sure, there  was some evidence  of participation by          Rood and-or Wallace in a few other incidents.  But the quantities          involved in  these incidents were  niggling in comparison  to the          Sepulveda trips and, thus, do not affect these appeals.                                          71          method  was to  construct a  double "average"  covering both  the          number of runs  and the amount of cocaine carried.  This was done          by  taking  the  midpoint  of   the  high  and  low  figures  and          multiplying the  average  number of  runs by  the average  amount          carried.  Thus, in Wallace's  case, the PSI Report assumed twelve          runs (an alleged "average" of ten and fifteen) and 556 grams  per          run  (the rounded-off average, expressed in grams, of four ounces          and  one kilogram),  attributing  a total  of  6.68 kilograms  of          cocaine to  him.  In  Rood's case, a different  probation officer          proposed  a  slightly   more  complicated  (but  methodologically          similar) calculation  and attributed 8.3  kilograms to him.   The          exact  mechanics  are beside  the  point; what  matters,  for our          purposes,  is  that,  albeit  somewhat  more  circuitously,   the          ultimate attribution  of a  drug quantity figure  to Rood,  as to          Wallace,  represented   an  assumed   average  number  of   trips          multiplied by an assumed average quantity of cocaine per trip.                    The district  court held  separate sentencing  hearings          for Rood and Wallace.  Neither the prosecution nor the defendants          offered additional evidence.  The court, over objection, endorsed          the probation  officers' calculations, attributing  8.3 kilograms          of cocaine to Rood and 7.6 kilograms  to Wallace.  This yielded a          base  offense level  (BOL)  of 32  for  each man.   See  U.S.S.G.                                                              ___           2D1.1(c) (6) (Drug Quantity  Table) (establishing BOL of 32  for          at least five  but less than fifteen kilograms of  cocaine).  The          court  essayed  further  offense-level  adjustments (not  now  in          dispute), factored Rood's criminal history category (IV) into the                                          72          mix,  and set  his guideline  sentencing range  (GSR) at  135-168          months.   The court sentenced  Rood at  the bottom of  the range.          Wallace  displayed a  less notorious  criminal history  (category          II).  Nonetheless,  after interim adjustments not  material here,          his GSR proved  to be  identical.   Relying on  United States  v.                                                          _____________          Floyd, 945 F.2d 1096, 1099 (9th Cir.  1991), and citing a lack of          _____          adult   guidance  during  Wallace's  youth,  the  court  departed          downward, sentencing him to ten years.30                    The defense's first line of attack is to assail Perez's          testimony as utterly unreliable in view of his dubious character,          asserted  contradictions, and  sundry other  defects.   But,  the          trial judge  heard and saw  Perez testify at trial,  and credited          his testimony.   Such credibility  calls are grist for  the trial          court's mill.   See St. Cyr, 977  F.2d at 706.   Consequently, we                          ___ _______          have no basis for overturning this judgment.                    Nonetheless, one swallow  does not a summer make.   The          critical problem  with respect to  these sentences lies  not with          Perez's testimony  but with  the pyramiding  of inferences  based          upon it.  Perez's testimony was elicited at  trial, not at either          sentencing hearing,  and  the  prosecution,  primarily  concerned          during trial with proving the defendants' participation in a drug          trafficking conspiracy rather than fixing the precise quantity of          drugs  for  which  each  defendant  might  be  held  responsible,                                        ____________________               30Floyd has since  been overruled, albeit on  other grounds.                 _____          See  United States  v. Atkinson,  990 F.2d  501 (9th  Cir. 1993).          ___  _____________     ________          However, the government has not prosecuted a cross-appeal and the          validity of the departure decision is not before us.                                          73          obtained  a  bare  minimum  of   information.    With  no  better          information  at  hand,  these  appellants'  sentences  cannot  be          upheld.                    For sentencing purposes, the government must prove drug          quantities by a preponderance of the evidence.  See United States                                                          ___ _____________          v. Sklar, 920 F.2d 107, 112-13 (1st Cir. 1990); Bradley, 917 F.2d             _____                                        _______          at 605.   Courts  must sedulously  enforce that  quantum-of-proof          rule, for,  under the  guidelines, drug  quantity has  a dramatic          leveraging   effect.     Thus,   relatively   small  quantitative          differences may produce markedly different periods of immurement.          This reality informs  the preponderance standard, requiring  that          district  courts   must   base  their   findings   on   "reliable          information" and, where uncertainty reigns, must "err on the side          of caution."   Sklar, 920 F.2d  at 113 (quoting United  States v.                         _____                            ______________          Walton, 908  F.2d 1289, 1302  (6th Cir.), cert. denied,  498 U.S.          ______                                    _____ ______          990 (1990)).                    These  tenets possess  particular force  on the  record          before  us, for  we do  not  believe that  the so-called  average          figures selected  by the  probation officers  and adopted  by the          trial court have adequate support in the record.  To say that the          minimum amount carried on a single  trip was four ounces and that          the maximum  was  one kilogram  provides  no rational  basis  for          presuming that  the average amount  carried on a given  number of          trips  was  the mathematical  midpoint between  the high  and low          figures.   Cf. United States v. Hewitt,  942 F.2d 1270, 1274 (8th                     ___ _____________    ______          Cir.   1991)  (condemning  use  of  a  "far  reaching"  averaging                                          74          assumptions in estimating  drug quantity).  Similarly,  while the          distortions are mathematically  less serious, the selection  of a          midpoint in  estimating  the  number of  trips  is  also  without          evidentiary support.   And the  two flawed findings feed  on each          other; by using not one,  but two, unsupported averages to arrive          at both the number of trips undertaken and the amounts of cocaine          handled  in the  course of  each trip,  the court  compounded the          error of its ways.   This is,  after all, not a  case in which  a          witness testified that, in his or her estimation,"X" equalled the          average  drug quantity  involved  in a  specific  number of  drug          transactions.   That  kind of  estimate  from a  lay witness  may          itself be  troublesome, but  at least the  witness can  be cross-          examined  on the figure;  and this  court has  sometimes accepted          such  estimates  in  the  past.   See,  e.g.,  United  States  v.                                            ___   ____   ______________          Innamorati, 996  F.2d 456, 490  (1st Cir.), cert. denied,  ___ S.          __________                                  _____ ______          Ct. ___ (1993).  It is also  not a case where a witness has given          a  range, as  to amounts  or  as to  trips, but  other persuasive          evidence (e.g., documents or records) exists tending to show that                    ____          some figure within  the range is supported by  a preponderance of          the evidence.  Here, to the contrary, the court did not cite, and          the PSI Report did not  identify, any extrinsic evidence or other          circumstances   making   averaging  peculiarly   appropriate   or          suggesting a  basis, apart from averaging, on which the probation          officers'  determinations  might rest.    For our  part,  we have          combed  the record and  unearthed nothing that  remotely suggests          Wallace joined in  transporting shipments averaging 556  grams or                                          75          that Rood's shipments averaged twelve  to sixteen ounces.  In the          face of timely objection, wholly conclusory findings such  as are          now before us  cannot be said  to command a preponderance  of the          evidence,  and,  therefore, cannot  support an  imposed sentence.          Cf., e.g., United States v. Shonubi, 998  F.2d 84, 89-90 (2d Cir.          ___  ____  _____________    _______          1993) (vacating,  in the  absence of  other evidentiary  support,          district  court's  drug  quantity  finding  arrived  at  by  rote          multiplication of number  of trips times quantity  carried on one          such trip);  United States v.  Garcia, 994 F.2d 1499,  1509 (10th                       _____________     ______          Cir.  1993)  (vacating  defendant's  sentence  and  holding  that          averages, when used to arrive  at drug quantity findings, must be          "more than a guess").  And the  gap in proof is not satisfied  by          showing, as  the government seeks to  do in its brief,  that more          trips and larger amounts are consistent with the general scale of          the Sepulveda enterprise.                    Let us be perfectly clear.  We do not announce a per se                                                                     ___ __          rule barring  a court from  sentencing at a point  different than          the low end of a testified range.  There may be other evidence in          the case,  direct or circumstantial,  making it more  likely than          not  that the  low point is  simply too  low and that  some other          point  is  more   probably  representative.    Indeed,   in  some          situations,  the  estimate  itself,  and  the  contextual  detail          surrounding  it, may  provide the  needed enlightenment.   In our          view, a  sentencing court remains  free to make judicious  use of          properly  constructed  averages  and,  ultimately,  to  make  any          finding that  the record supports.   See United States  v. Miele,                                               ___ _____________     _____                                          76          989 F.2d 659, 664-65 (3d Cir. 1993) (explaining that, where there          is  other  evidence  tending  to  buttress the  high  end  of  an          estimated range, the sentencing court need not restrict itself to          the range's low end); see  also U.S.S.G.   6A1.3(a) (stating that                                ___  ____          the  information on  which  a  sentence  is  based  must  possess          "sufficient  indicia  of  reliability  to  support  its  probable          accuracy").   Here,  however, the  record  does not  justify  the          district  court's findings  concerning  the  drug  quantities  it          attributed  to Rood  and  Wallace.    Accordingly,  because  drug          quantity dictated these  appellants' offense levels and  at least          arguably  influenced  their  sentences,  Rood   and  Wallace  are          entitled to be resentenced.31                                  C.  Kevin Cullinane.                                 C.  Kevin Cullinane.                                     _______________                    After all relevant adjustments had been made, the court          below established a GSR of 121-151  months referable to appellant          Cullinane,32  and  sentenced him  at  the  range's  nadir.   This          determination  rested in  substantial part  on  the court's  drug                                        ____________________               31On remand, the district court  is, of course, free to hear          new evidence bearing on drug quantity.  For example, it  may well          be that better evidence  can be adduced by recalling  Perez or by          calling other witnesses.   Alternatively, the government  has the          "low point" estimates as to both  the number of trips and amounts          transported to fall back upon   and it has some specific evidence          as to other transactions.  To start a mini-trial on drug quantity          is surely a  discouraging supplement to a lengthy  trial; but too          much rides  on the  computations to  rely upon the  kind of  drug          quantity calculations  that the  government urges  in respect  to          these two appellants.               32We  do not  dissect the  interim  adjustments made  by the          district court en route to  the GSR as Cullinane concentrates his          fire on the  drug quantity finding.  We follow this same pattern,          whenever applicable, in discussing other appellants' sentences.                                          77          quantity  assessment.    Cullinane  challenges  this  assessment,          insisting that Judge Devine erred in ascribing 8.99  kilograms of          cocaine to him.                    Our   review   of   Cullinane's   challenge   is   more          circumscribed  than  might  appear   at  first  blush.    It   is          unnecessary  to   address  an   allegedly  erroneous   sentencing          computation if,  and to the  extent that, correcting it  will not          change  the applicable offense  level or otherwise  influence the          defendant's  GSR (and,  ultimately, his  sentence).   See  United                                                                ___  ______          States  v. Connell,  960  F.2d  191, 198  n.11  (1st Cir.  1992);          ______     _______          Bradley, 917 F.2d at 604; see also Williams v. United States, 112          _______                   ___ ____ ________    _____________          S. Ct.  1112, 1121 (1992) (stating that an error in sentencing is          harmless,  and may  be disregarded,  if  it "did  not affect  the          district  court's  selection  of the  sentence  imposed").   This          principle is pertinent in Cullinane's  case:  his BOL, and, thus,          his sentence, will remain unchanged  so long as he is responsible          for an amount of cocaine between five and fifteen kilograms.  See                                                                        ___          U.S.S.G.  2D1.1(c)(6) (Drug  Quantity Table).  His  appeal fails,          then,  if there  is record  support for  ascribing at  least five          kilograms of cocaine to him.                    We find  this to  be the case.   Although  the district          court  relied  on the  testimony  of  a  number of  witnesses  to          buttress the  drug quantity it  attributed to Cullinane,  we need          not go beyond the testimony of David Chase.  Chase stated that he          bought somewhere between five and eight kilograms of cocaine from          Cullinane.  The district court  found this testimony credible and                                          78          we,  therefore, give  it  weight.    At  sentencing,  credibility          determinations  are the  province  of the  district  court.   See                                                                        ___          United States v.  Brewster, 1 F.3d  51, 55 (1st  Cir. 1993);  St.          _____________     ________                                    ___          Cyr, 977 F.2d at 706; see also 18  U.S.C.   3742(e) (1988).  That          ___                   ___ ____          ends  the matter:   the  lowest  of Chase's  estimates affords  a          sufficient predicate for the disputed sentence.                    Cullinane  attempts  to  confess and  avoid.    Even if          Chase's  testimony is reliable,  he ruminates, the  conduct Chase          describes is irrelevant to the charged conspiracy.  This maneuver          takes  appellant  down  a  blind alley.    Within  broad  limits,          reviewing courts must defer to a sentencing judge's determination          of  relevant  conduct.    Such  findings  are  almost  invariably          factbound, and  we will set them aside only  if they are shown to          be clearly  erroneous.  See Garcia, 954  F.2d at 16; Bradley, 917                                  ___ ______                   _______          F.2d at 605.   In addition, the argument for deference peaks when          the sentencing  judge has  presided over a  lengthy trial  and is          steeped in the  facts of the case.   See, e.g., United  States v.                                               ___  ____  ______________          Shattuck, 961  F.2d 1012, 1014-15 (1st Cir.  1992); United States          ________                                            _____________          v. Zuleta-Alvarez, 922 F.2d 33, 37 (1st Cir. 1990), cert. denied,             ______________                                   _____ ______          111 S. Ct. 2039 (1991).                    These salutary  precepts are  dispositive  here.   Full          deference is  due and  Chase's testimony, though  circumstantial,          touched upon,  and could logically  be found to  involve, matters          coming  within  the scope  of the  conspiracy.   Accordingly, the          lower court  did  not  commit  clear  error  in  concluding  that          Cullinane's transactions  with Chase  comprised relevant  conduct                                          79          for sentencing purposes.                                  D.  Arline Welch.                                  D.  Arline Welch.                                      ____________                    The  district court attributed 1924 grams of cocaine to          Arline  Welch  and imposed  the  mandatory  minimum incarcerative          sentence under 21 U.S.C.   841(b)(1)(B), viz., five years.  Welch                                                   ____          contests  only the  district  court's drug  quantity  assessment.          Because  the mandatory minimum  applies so long  as quantities of          cocaine totalling 500  grams or more are involved  in the offense          of conviction,  see id., we  need only inquire whether  that much                          ___ ___          contraband can fairly be attributed to her.                    We answer this  query affirmatively.   Perez  testified          that  Arline Welch accompanied him  on three journeys to Lawrence          and that 10  ounces of cocaine were  acquired on each trip.   The          district court credited Perez's testimony, attributing nearly 900          grams of  cocaine to  Arline Welch on  this account.   We decline          appellant's invitation to second-guess this finding.                                   E.  Edward Welch.                                  E.  Edward Welch.                                      ____________                    The district court attributed 7.72 kilograms of cocaine          to Edward Welch and, after various interim adjustments, sentenced          him to  135 months  in prison (the  low end  of the GSR).   Welch          challenges only the drug quantity assessment.                    The  court's  attribution  of cocaine  to  Edward Welch          rests upon a cornucopia of  testimony.  It would serve  no useful          purpose to survey it all.  Upon  careful review of the record, we          can see, at a minimum, no clear error in the court's  decision to          accept the testimony  of Coriaty and Milne    testimony that was,                                          80          in  itself, sufficient  to support  the attribution  of over  5.3          kilograms to  this defendant.33   At this  point, Welch's  ground          of appeal collapses,  for his sentence  would be the same  if the          court had  found 5.3 kilograms  rather than 7.72 kilograms.   See                                                                        ___          U.S.S.G.  2D1.1(c)(6) (Drug Quantity Table).                                 F.  Cheryl Johnson.                                 F.  Cheryl Johnson.                                     ______________                    The  lower court attributed 1.2 kilograms of cocaine to          Cheryl  Johnson  and  imposed  the  mandatory  minimum  five-year          sentence.   See 21 U.S.C.    841(b)(1)(B).  Johnson  disputes the                      ___          drug quantity  finding.  Here,  again, the trigger amount  is 500          grams of cocaine.  See id.                             ___ ___                    The district court determined, inter alia, that Johnson                                                   _____ ____          sold 1/16th  of an  ounce of cocaine  to Santos  on at  least 100          occasions; and that she sold 3/10s of an ounce to  officer Malone          on another occasion.  The  court further found that $7,115 seized          from  Johnson's house constituted the proceeds of drug sales and,          for sentencing purposes, equated this cash stash with 5.08 ounces          of cocaine.   Finally, the court credited  Perez's testimony that          Johnson  participated in  at  least  "a  couple"  of  drug-buying          expeditions.   Erring  on the  side of  caution, the  court could          warrantably   have  found  Johnson  responsible  for  two  trips,                                        ____________________               33At the  risk of carrying  coal to Newcastle, we  note that          Edward Welch  was a  fellow traveller on,  and a  co-venturer in,          several  drug-buying  expeditions  described  supra  Part  XI(D).                                                        _____          Thus, the drug  quantities associated with those  jaunts are also          attributable to him.                                          81          involving  four  ounces  per  trip.34    In  the  aggregate,  the          determinations  listed above support the attribution of 556 grams          of  cocaine  to Johnson     more  than  the minimum  required  to          underbrace the sentence she received.                    Johnson  argues against these  serial findings on three          grounds.  Her first attack   a broadside blast aimed at the total          quantity  of cocaine attributed to her   deserves little comment.          We simply restate the obvious:   the district court's credibility          calls  are  beyond  reproach   and,  therefore,  its  bottom-line          conclusion is not clearly erroneous.                    Johnson's  second  fusillade  is  aimed   at  the  cash          equivalency finding.  In drawing a head on the sentencing court's          decision to  translate dollars  into drugs,  Johnson is  shooting          blanks.   The government presented abundant evidence of Johnson's          narcotics trafficking, see  supra Part II(D),  and the volume  of                                 ___  _____          business  transacted justified the court's illation that the sums          seized  were  connected  to  her  drug  dealings.    When  it  is          reasonably probable that confiscated cash  represents either drug          profits   or  money  dedicated   to  the  upcoming   purchase  of          contraband,   a  sentencing  court  may  convert  the  cash  into          equivalent  amounts of narcotics for "relevant conduct" purposes.          See U.S.S.G.   2D1.4, comment. (n.2) (authorizing district courts          ___          to use price as a means of approximating drug quantity); see also                                                                   ___ ____                                        ____________________               34The court actually found that Johnson's two trips involved          16 ounces per trip.   But, this finding utilized an impermissible          process of rote averaging.  See supra  Part XI(B).  Hence, we use                                      ___ _____          the low end of the range  of available estimates for purposes  of          appellate review.                                          82          United States v. Jackson, 3 F.3d 506, 510 (1st Cir. 1993); United          _____________    _______                                   ______          States v. Figueroa, 976 F.2d 1446, 1460-61 (1st Cir. 1992), cert.          ______    ________                                          _____          denied, 113  S. Ct.  1346 (1993); United  States v.  Gerante, 891          ______                            ______________     _______          F.2d 364, 369 (1st Cir. 1989).  So it is here.                    Johnson's  third salvo also  flies wide of  the target.          She insists that the cash did not belong to her and, thus, cannot          figure  in  her  sentence.   But  as  we  read  the  record,  the          circumstantial  evidence   supports  a  finding   of  proprietary          interest.   And, moreover, even  if we were  to give credence  to          Johnson's  protest  regarding  ownership,  the  cash  equivalency          evidence could  be used against  her as  long as  the drug  money          constituted part  of the same common  scheme or plan  and met the          foreseeability  requirement   for  relevant  conduct   under  the          guidelines.  See Garcia, 954 F.2d at 15; Blanco, 888 F.2d at 910-                       ___ ______                  ______          11; see also  supra Part  XI(A) (discussing  relevant conduct  in              ___ ____  _____          conspiracy  cases).    The  evidence  here  could  reasonably  be          interpreted as  placing the  cash stash within  the orbit  of the          conspiracy.   For these reasons, we detect  no clear error in the          lower  court's conclusion  that the  money ought  properly to  be          treated  as  a  proxy  for  cocaine  and  counted   against  this          appellant.                    Johnson  has two  final  items  in  her  asseverational          array.  She asserts that the court should have reduced her BOL by          two levels since  she was merely a minor participant  in the drug          distribution scheme, see  U.S.S.G.  3B1.2(b), and that  the court                               ___          should  have departed downward  due to her  family circumstances.                                          83          Neither assertion has much firepower.                    As  to   the  former   plaint,  a   role-in-the-offense          reduction,  even if granted, would  have no effect on appellant's          sentence  due to the  overriding force  of the  mandatory minimum          prescribed by 21 U.S.C.    841(b)(1)(B).  See U.S.S.G.   5G1.1(b)                                                    ___          (providing that  the statutorily required  minimum sentence shall          be  the  guideline  sentence  when  it exceeds  the  top  of  the          applicable GSR).  The assignment of error is, therefore, moot.                    As  to  Johnson's last  point,  it is  settled  in this          circuit  that a  sentencing  judge's  informed  decision  not  to          depart, regardless of direction, is a non-appealable event.   See                                                                        ___          United States  v. Tardiff, 969  F.2d 1283, 1290 (1st  Cir. 1992);          _____________     _______          United  States v.  Hilton, 946  F.2d  955, 957  (1st Cir.  1991).          ______________     ______          There is nothing about  appellant's case that extricates it  from          the vice-like  grip of this  jurisdictional rule.  In  any event,          appellant failed  to seek  a departure below  and, hence,  cannot          broach the matter for the first  time on appeal.  See Ortiz,  966                                                            ___ _____          F.2d  at  717 (reiterating  rule  that appellate  court  will not          address  sentencing arguments that  were not  seasonably advanced          below); United States v.  Dietz, 950 F.2d 50, 55  (1st Cir. 1991)                  _____________     _____          (similar).          XII.  CONCLUSION          XII.  CONCLUSION                    We  need go  no  further.   After  considering all  the          issues   raised  by   appellants,  including   some  issues   not          specifically  discussed herein, we  have unearthed no  vestige of          reversible error.    Appellants' convictions  and  sentences  are                                          84          therefore lawful, save only for the sentences imposed on Rood and          Wallace.   Accordingly, we affirm  the convictions  of those  two          appellants, vacate their sentences,  and remand for resentencing.          At the same  time, we affirm the convictions and sentences of the          other eight appellants.   We stay issuance of mandate in  all the          appeals, pending publication  of the two additional  (and closely          related) opinions described supra note 2.                                      _____                    The  convictions  and  sentences  of  appellants  David                    The  convictions  and  sentences  of  appellants  David                    _______________________________________________________          Sepulveda,  Edgar  Sepulveda,  Edward W.  Welch,  Jr.,  Arline S.          Sepulveda,  Edgar  Sepulveda,  Edward W.  Welch,  Jr.,  Arline S.          _________________________________________________________________          Welch, Kevin Cullinane, Cheryl T. Johnson, Richard F. Labrie, and          Welch, Kevin Cullinane, Cheryl T. Johnson, Richard F. Labrie, and          _________________________________________________________________          Ernest F. Langlois are affirmed in all respects.  The convictions          Ernest F. Langlois are affirmed in all respects.  The convictions          _______________________________________________   _______________          of appellants  Tony  Rood and  William D.  Wallace are  affirmed,          of appellants  Tony  Rood and  William D.  Wallace are  affirmed,          _________________________________________________________________          their sentences  are vacated, and,  as to those  appellants only,          their sentences  are vacated, and,  as to those  appellants only,          _________________________________________________________________          the case is  remanded for resentencing.  The  issuance of mandate          the case is  remanded for resentencing.  The  issuance of mandate          ______________________________________   ________________________          is stayed pending further order of the court.          is stayed pending further order of the court.          ____________________________________________                                          85
