January 5, 1993   UNITED STATES COURT OF APPEALS
                      FOR THE FIRST CIRCUIT

                                             

No. 92-1426

                    UNITED STATES OF AMERICA,

                            Appellee,

                                v.

                       MARCO A. ECHEVERRI,

                      Defendant, Appellant.

                                             

           APPEAL FROM THE UNITED STATES DISTRICT COURT

                 FOR THE DISTRICT OF RHODE ISLAND

      [Hon. Raymond J. Pettine, Senior U.S. District Judge]
                                                          

                                             

                              Before

                      Selya, Circuit Judge,
                                          

                  Bownes, Senior Circuit Judge,
                                              

                    and Stahl, Circuit Judge.
                                            

                                             

     Edward  C.  Roy, with  whom  Roy &amp;  Cook  was on  brief, for
                                             
appellant.
     Zechariah  Chafee, Assistant  United  States Attorney,  with
                      
whom Lincoln C. Almond, United States Attorney, was on brief, for
                      
the United States.

                                             

                                             

          SELYA, Circuit  Judge.   Defendant-appellant  Marco  A.
          SELYA, Circuit  Judge.
                               

Echeverri  asks  us  to  overturn  his  conviction  on two  drug-

trafficking charges.   He alleges that the proof was insufficient

to support the jury's verdict; that the government never properly

authenticated  a "drug ledger;" and that the court below erred in

permitting an expert witness to testify  concerning the import of

the disputed document.  Discerning no error, we affirm.

I.  BACKGROUND

          We  limn the facts in  the light most  favorable to the

government, consistent  with record  support.  See,  e.g., United
                                                                 

States v. Maraj, 947 F.2d 520, 522 (1st Cir. 1991).
               

          Armed with a  search warrant, a team of law enforcement

officers  including FBI  Special  Agent  Frederick  Ghio  entered

appellant's  apartment in  Pawtucket, Rhode  Island.   The living

quarters consisted of a narrow bedroom, a multi-purpose room, and

a bathroom, having a total combined area roughly equal to that of

a  one-car garage.  When  the agents arrived,  Victor Gallego was

leaving the bathroom  and appellant was seated at a  table in the

multi-purpose room.  Next to appellant, on the couch and in plain

view, lay an earnings statement in his name.  On the back of this

statement  was a  handwritten column  of numbers  arrayed  in the

following fashion:

                                2

           1000
           2000
          17000
           1000
          10000
           4000
           1000
               
          34000

          In  the course of the ensuing search the agents found a

tape-wrapped  block  of cocaine     eighty-six  percent pure  and

weighing about  two pounds    on the  toilet lid.   The tape  had

broken and the contraband  was exposed.  An electronic  scale lay

nearby. 

          Gallego  and Echeverri were  charged with possession of

cocaine with  intent to distribute  it, 21  U.S.C.     841(a)(1);

841(b)(1)(B), and  with  participating  in  a  drug  distribution

conspiracy.  21 U.S.C.   846.  Gallego  pled guilty and Echeverri

stood trial alone.  Over his objection, the government introduced

the earnings statement  into evidence.   The court allowed  agent

Ghio to  testify that, in  his opinion, the  reverse side  of the

statement  comprised  a  drug  ledger  (the   individual  figures

corresponding to  per-ounce prices  for various cocaine  sales in

the Rhode Island  market).   Ghio further testified  that it  was

common  for  cocaine  dealers  to  keep  their  accounts in  such

fashion;  that the going price for cocaine was $35,000 to $40,000

per  kilogram; that the total shown on the earnings statement, if

interpreted to mean "dollars" and  added correctly,1 corresponded

                    

     1The column  of figures, added  correctly, totalled  37,000,
not 34,000.  We consider this mathematical mishap unimportant.

                                3

in rough proportion  to the  gross sales price  of the  aggregate

cocaine  on hand; and that  the quantity of  narcotics seized was

inconsistent with personal use.

          The  jury convicted  Echeverri  on both  counts.   This

appeal ensued.

II.  SUFFICIENCY OF THE EVIDENCE

          Appellant labors to convince us that the judgment below

rests  on  too fragile  an evidentiary  foundation.   We  are not

persuaded.

                     A.  Standard of Review.
                                            

          The  standard of  review applicable  to sufficiency-of-

the-evidence  challenges is  settled.   An  appellate court  must

examine  the  evidence  in  the  light  most  flattering  to  the

prosecution, indulging all reasonable inferences in its favor and

then determining  whether a rational jury could find guilt beyond

a reasonable doubt.  See, e.g., Maraj, 947 F.2d at 522-23; United
                                                                 

States v. Boylan, 898 F.2d 230, 243 (1st Cir.), cert. denied, 111
                                                            

S.Ct. 139 (1990).   In making this determination, the  court must

credit both direct and  circumstantial evidence   and it  must do

so without evaluating the relative  weight of different pieces of

proof  or   venturing  credibility   judgments.    To   uphold  a

conviction, the court need not believe that no verdict other than

a guilty verdict could sensibly be reached, but must only satisfy

itself that  the guilty  verdict finds  support  in "a  plausible

rendition of the record."  United States v.  Ortiz, 966 F.2d 707,
                                                  

711 (1st Cir. 1992),  petition for cert. filed (U.S.  October 19,
                                              

                                4

1992) (No. 92-6552).

            B.  Possession with Intent to Distribute.
                                                     

          In challenging  his conviction on  the specific-offense

count, appellant questions whether the evidence is copious enough

to  sustain a finding that  he knowingly possessed  cocaine.  The

government, he says, proved no more than his "mere presence" at a

site where drugs were found. 

          The  "mere presence" defense has become, at one and the

same time,  both the  last  haven of  the innocent  and the  last

refuge  of  the  scoundrel.    Although  courts  have  found   it

applicable in  certain situations,  United States v.  Barnes, 890
                                                            

F.2d  545, 549 (1st Cir. 1989)  (collecting cases), cert. denied,
                                                                

494  U.S.  1019  (1990), the  mere  presence  defense  is not  so

ubiquitous as to envelop every drug-trafficking case in which the

government  lacks direct  evidence of  a defendant's  complicity.

The defendant's presence at a place where contraband is found may

or may not  be purely coincidental.  The  attendant circumstances

tell the tale    and  the culpability of  a defendant's  presence

hinges upon whether the circumstances fairly imply  participatory

involvement.    In other  words,  a  defendant's "mere  presence"

argument will fail in situations where the "mere" is lacking.  

          This is such  a situation.   There is  far more to  the

prosecution's case against Echeverri  than his corporeal presence

in the apartment.  A rational jury, drawing reasonable inferences

from proven facts, could certainly have concluded that this was a

case of culpable presence as opposed to mere presence, see Ortiz,
                                                                

                                5

966 F.2d at 712, and that appellant was in knowing possession  of

the contraband at the time of the raid.  We explain briefly.

          Both constructive  possession and guilty  knowledge may

be  inferred from a defendant's dominion and control over an area

where narcotics are  found.  See, e.g., Barnes, 890  F.2d at 549.
                                              

In this  instance, there is considerable evidence of dominion and

control.  Appellant  concedes that the  apartment was his  abode.

His  rent receipts,  passport,  and other  personal effects  were

strewn about  the premises.  As the  lessee of the apartment, and

the one who  called it  home, appellant was  hardly powerless  to

determine who and what could come inside.2

          Moreover, the  entire apartment consisted  of a  small,

cramped space.  The  cocaine was in plain view, resting openly on

the  dwelling's  only  toilet.   Tools  of  the  drug trade  were

conspicuously  displayed.     Echeverri  himself  was  physically

present, seated within four feet of  the contraband.  All in all,

the  totality of  the circumstances  suffices  to support  both a

finding  of  constructive  possession  and a  finding  of  guilty

knowledge.  See, e.g., United States v. Gonzalez-Torres,     F.2d
                                                       

   ,      [No. 91-2140, slip op. at 2-6]; Ortiz, 966 F.2d at 713-
                                               

14;  United  States v.  Desmarais, 938  F.2d  347, 352  (1st Cir.
                                 

1991); United  States v.  Batista-Polanco, 927  F.2d 14, 19  (1st
                                         

Cir. 1991); Barnes, 890 F.2d at 549-51; see also United States v.
                                                              

                    

     2The  fact  that  appellant,  as the  sole  rent  payer  and
resident  of the dwelling, had the exclusive right to control the
comings and goings there is one of several important distinctions
between this case and  United States v. Ocampo, 964  F.2d 80 (1st
                                              
Cir. 1992), much bruited by appellant.

                                6

Calle-Cardenas, 837 F.2d  30, 32 (1st  Cir.) (where apartment  in
              

which   defendant   was   found   contained   his   clothes   and

identification   cards,   he  had   dominion  and   control  over

apartment), cert. denied,  485 U.S. 1024 (1988); United States v.
                                                              

Lochan, 674  F.2d  960, 965-66  (1st  Cir. 1982)  (defendant  had
      

dominion  and control over area behind back seat of automobile he

was driving and,  therefore, over hashish  stowed in that  area).

          The evidence  was also  ample to sustain  a finding  of

scienter.  We have  repeatedly held, and today reaffirm,  that an

intent  to distribute  drugs  can legitimately  be inferred  from

factors such as quantity and purity.  See, e.g., United States v.
                                                              

Ocampo-Guarin, 968  F.2d 1406,  1410 (1st Cir.  1992) (collecting
             

cases); Batista-Polanco, 927 F.2d at 18-19.  Such factors prevail
                       

here.  Furthermore, agent Ghio's  testimony adds strength to  the

relevant evidentiary predicate.  

          We  will not paint the  lily.  Because  we require only

that  a jury's verdict be supportable, not that it be inevitable,

see  Boylan,  898  F.2d  at   243,  we  must  affirm  appellant's
           

conviction for possession with intent to distribute.

                         C.  Conspiracy.
                                        

          Appellant's  challenge  to  his  conspiracy  conviction

fares  no  better.   To  support  a  conspiracy  conviction,  the

prosecution  must prove  certain  things not  required under  the

specific-offense  count.    It must  show,  inter  alia,  that an
                                                       

agreement  or  working  relationship  existed,  that  it  had  an

unlawful  purpose,  and  that   the  defendant  was  a  voluntary

                                7

participant in it.  See United States v. David, 940 F.2d 722, 735
                                              

(1st Cir. 1991),  cert. denied,  112 S.Ct. 605,  908, 1298,  2301
                              

(1992);  United States  v. Rivera-Santiago,  872 F.2d  1073, 1079
                                          

(1st Cir.), cert.  denied, 492  U.S. 910 (1989).   The  agreement
                         

itself "need  not be express, but  may consist of no  more than a

tacit understanding."  United  States v. Glover, 814 F.2d  15, 16
                                               

(1st Cir.  1987) (citations and quotation  marks omitted); accord
                                                                 

United  States v.  Paiva,  892 F.2d  148,  161 (1st  Cir.  1989).
                        

Moreover, the  proof of a defendant's  conspiratorial involvement

may consist of indirect evidence, including reasonable inferences

drawn from attendant  circumstances.  See, e.g.,  David, 940 F.2d
                                                       

at  735;  Glover,  814 F.2d  at  16-17.   In  the  last analysis,
                

criminal  juries are  not expected  to ignore  what  is perfectly

obvious.  See United States  v. Ingraham, 832 F.2d 229, 240  (1st
                                        

Cir. 1987), cert. denied, 486 U.S. 1009 (1988). 
                        

          In  this  case,  there was  evidence  that,  in a  tiny

apartment, within feet of  the sole tenant, law officers  found a

commercially  exploitable  quantity  of  high-purity  cocaine,  a

measuring scale of the sort frequently used by narcotics  dealers

to ply their trade, and a drug ledger (written on the back of the

tenant's pay stub).   Exiting from the room where the cocaine lay

open  and exposed  was  another man  (Victor  Gallego).   A  jury

viewing this evidence could reasonably conclude that  the two men

had agreed to disobey the law and distribute cocaine.  Cf., e.g.,
                                                                

Ortiz,  966  F.2d at  712 (criminals  "rarely seek  to perpetrate
     

felonies   before  larger-than-necessary   audiences");  Batista-
                                                                 

                                8

Polanco, 927 F.2d  at 18-19 (similar);  United States v.  Cuevas-
                                                                 

Esquivel, 905 F.2d  510, 515 (1st Cir.)  (similar), cert. denied,
                                                                

111 S.Ct. 208 (1990).

III.  OTHER ASSIGNMENTS OF ERROR

          We consider appellant's  assignments of mid-trial error

in the ensemble.

                       A.  Authentication.
                                          

          Appellant  complains  that  the  government  failed  to

authenticate  the so-called  drug ledger as  required by  Fed. R.

Evid. 901,  and that, consequently,  the district court  erred in

admitting  it into  evidence.3     We  review the  trial  court's

rulings concerning authentication  of documents only  for mistake

of  law or  abuse of  discretion.   See Ortiz,  966 F.2d  at 716;
                                             

United States v. Ladd, 885 F.2d 954, 956 (1st Cir. 1989).
                     

          When the authenticity of  a document is challenged, the

court must determine whether  there is sufficient threshold proof

that the  document is what  its proponent claims  it to be.   See
                                                                 

                    

     3The rule provides in pertinent part:

          The   requirement    of   authentication   or
          identification  as  a condition  precedent to
          admissibility   is   satisfied  by   evidence
          sufficient  to  support  a finding  that  the
          matter  in  question  is  what  its proponent
          claims.

Fed. R. Evid. 901 (a).

                                9

Ortiz, 966  F.2d at 716.   The Federal Rules of  Evidence adopt a
     

flexible approach to this question.   Indeed, the applicable rule

suggests  that the  "[a]ppearance, contents,  substance, internal

patterns,   or  other   distinctive  characteristics,   taken  in

conjunction  with    circumstances,"  can  confirm  a  document's

authenticity.  Fed. R. Evid. 901(b)(4).

          In  this instance,  the  government  claimed  that  the

earnings  statement doubled as a drug ledger.  The district court

admitted the evidence  on that basis.  We discern  no error.  The

earnings  statement was  clearly identified  with Echeverri    it

was,  after all, a recapitulation  of his wages,  reposing in his

apartment.   Federal agents discovered  the document  lying on  a

couch  within  feet of  a  sizable,  easily  visible  package  of

cocaine.  The column of handwritten figures on the paper totalled

37,000   the approximate  dollar value of the discovered  cocaine

in the  local market.  Finally,  an agent familiar with  the drug

trade testified on voir dire that he believed the  document was a

drug  ledger  and gave  persuasive  reasons  in support  of  that

conclusion.  No more was exigible.  

          To be  sure, the  government presented no  direct proof

that Echeverri  authored the jottings on  the earnings statement.

But,  such proof was not  a prerequisite to  admissibility in the

circumstances  at bar.  On  the record before  us, the government

sufficiently connected  the document to the conspiracy and to the

appellant, even though it did not conclusively prove the author's

identity.  Cf.,  e.g., United  States v. Natale,  526 F.2d  1160,
                                               

                                10

1173 (2d  Cir. 1975) (holding that,  for authentication, "[p]roof

of the  connection of an exhibit to the defendants may be made by

circumstantial, as well as  direct, evidence"), cert. denied, 425
                                                            

U.S.  950 (1976).  Whether  Echeverri, his coconspirator, or some

third person  was the one who actually put pen to paper and wrote

down the figures is of no moment.  Regardless,  the evidence that

identified the document as a drug ledger was the key to the issue

of  authentication.  See United  States v. Smith,  918 F.2d 1501,
                                                

1510 (11th Cir. 1990),  cert. denied, 112 S.Ct. 151,  253 (1991);
                                    

United States v. Drougas, 748 F.2d 8, 26 (1st Cir. 1984).4
                        

                      B.  Expert Testimony.
                                           

          Appellant also  contends that the  district court erred

in allowing agent Ghio  to offer opinion evidence anent  the drug

ledger.  His contention is unavailing.  

          We have consistently  recognized that academic training

is  not a  sine  qua  non  of  expert  knowledge  concerning  the

                    

     4The cases  cited by appellant  in support of  his challenge
are  readily distinguishable.   In both United  States v. Mouzin,
                                                                
785 F.2d  682 (9th Cir.), cert.  denied, 479 U.S. 985  (1986) and
                                       
United  States  v. Ordonez,  737 F.2d  793  (9th Cir.  1983), the
                          
government   argued  that  intricately   detailed  writings  were
properly  admitted into evidence to prove the truth of the matter
asserted  therein because    the  writings  were  coconspirators'
statements or statements of  a party opponent.  In  this context,
the  Ninth Circuit found error  because there was  no evidence of
actual authorship and, therefore, no foundation for the admission
of such statements.   See Mouzin, 785  F.2d at 692; Ordonez,  737
                                                           
F.2d at 800-02; see also  Fed. R. Evid. 801(d)(2).   In contrast,
                        
there  has  been  no suggestion  in  the  instant  case that  the
document was admitted to  prove the truth of the  matter asserted
therein.   Rather, the  jottings on this  sheet are  more akin to
physical  evidence  of  the   crime  than  to  potential  hearsay
statements.   See, e.g., United  States v. Wilson,  532 F.2d 641,
                                                 
645-46 (8th Cir.), cert. denied, 429 U.S. 846 (1976).  
                               

                                11

practices  of  hard-core drug  traffickers.    See, e.g.,  United
                                                                 

States v. Hoffman, 832  F.2d 1299, 1310 (1st Cir. 1987).  Perhaps
                 

realizing  the  durability  of  this tenet,  appellant  does  not

question Ghio's qualifications to serve as an expert witness.  He

does, however, question the need for expert testimony.

          In   deciding  whether  to  admit  or  exclude  opinion

evidence, courts  must assess  whether the testimony  will likely

assist  the jury in  understanding the proof  or ascertaining the

facts.    See Fed.  R.  Evid. 702.    Because  of its  first-hand
             

acquaintance with  the case, the trial court  enjoys broad leeway

in making this discretionary determination.  The court of appeals

will overturn a 

trial-level determination  about the  need  for expert  testimony

only  if a manifest  abuse of the trial  court's discretion is in

prospect.  See Ladd, 885 F.2d  at 959; Hoffman, 832 F.2d at 1310.
                                              

          Here,  the  central  issue   on  count  2  was  whether

appellant   was     or  was  not     a  knowing  and  intentional

participant  in  a  cocaine  conspiracy.   Ghio's  testimony  was

clearly  relevant to  that issue.   Moreover,  the testimony  was

undoubtedly helpful to  the jury.   Laymen, on  average, are  not

familiar with the praxis of the cocaine community.  See Ladd, 885
                                                            

F.2d at 960.  It follows that a trial court may allow a qualified

expert to  identify an otherwise  inscrutable document as  a drug

ledger and explain  its contents.   See, e.g.,  United States  v.
                                                             

Campino, 890 F.2d 588, 593 (2d Cir. 1989), cert. denied, 494 U.S.
                                                       

                                12

1068, (1990); United States v. Diaz, 878 F.2d 608, 619 (2d  Cir),
                                   

cert. denied, 493 U.S.  993 (1989); United States v.  DeSoto, 885
                                                            

F.2d 354, 362 (7th Cir.  1989); see also United States v.  Rubio-
                                                                 

Estrada, 857 F.2d 845 (1st Cir. 1988) (noting approvingly, albeit
       

without considering the issue raised by this  appellant, that the

jury had before it  the expert testimony of a  government witness

who identified and  explained a  drug ledger).   The lower  court

acted  well within the encincture of its discretion in permitting

the use of such evidence here.5      

IV.  CONCLUSION

          We  need   go  no  further.     The  government  proved

Echeverri's  guilt beyond a reasonable doubt in a trial free from

reversible 

error.  The judgment below is therefore

Affirmed.
        

                    

     5We  note  that the  district  court  wisely instructed  the
jurors  that   agent  Ghio's  opinion   testimony,  like  opinion
testimony generally, was not binding upon them.

                                13
