                  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 &amp; Cherry  was on brief,
                                                  
for defendant Edward W. Welch, Jr.
     Kevin M. Fitzgerald, with whom Peabody &amp; 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  &amp;
                                                                 
Lahey, P.A. was on brief, for defendant William D. Wallace.
           
     Julie  L. Lesher,  with whom  Murphy,  McLaughlin, Hemeon  &amp;
                                                                 
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
                                                                 
&amp;  Middleton, Peabody  &amp; 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

          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

          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.
                                        

          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.
                                          

          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.
                                          

          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.
                                         

          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

          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.
                                      

          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 &amp; 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.
                                                 

          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 &amp; 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

          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.
                                           

                                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.
                                          

          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

          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.
                                            

                    

     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.
                                             

          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 &amp; 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

          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.
                                            

          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 &amp; 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.
                                               

                    

     15When  uncertainty attends a  proffer of  opinion evidence,
voir dire screenings are standard  fare.  See, e.g., Tokio Marine
                                                                 
&amp; Fire Ins. Co. v. Grove Mfg. Co., 958 F.2d 1169, 1175 &amp; 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

          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.
                                                  

          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.
                                              

          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

          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

          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

          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.
                                                  

          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.
                                            

          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.
                                        

          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.
                                              

          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.
                                               

          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.
                                         

          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.
                                       

          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.
                                              

          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.
                                          

          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

          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.
                                           

          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 &amp; 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.
                                               

          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.
                                          

          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.
                                        

          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.
                                        

          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.
                                         

          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

          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
                                                                 

Sepulveda,  Edgar  Sepulveda,  Edward W.  Welch,  Jr.,  Arline S.
                                                                 

Welch, Kevin Cullinane, Cheryl T. Johnson, Richard F. Labrie, and
                                                                 

Ernest F. Langlois are affirmed in all respects.  The convictions
                                                                 

of appellants  Tony  Rood and  William D.  Wallace are  affirmed,
                                                                 

their sentences  are vacated, and,  as to those  appellants only,
                                                                 

the case is  remanded for resentencing.  The  issuance of mandate
                                                                 

is stayed pending further order of the court.
                                            

                                85
