Court Opinion

ID: 2963571
Source: CourtListenerOpinion
Date Created: 2015-09-21 21:12:12.994538+00
Date Added: 2024-06-11T11:42:43.063062
License: Public Domain

USCA1 Opinion

	

                            United States Court of Appeals
                            United States Court of Appeals
                                For the First Circuit
                                For the First Circuit
                                 ____________________

        No. 94-1301

                                    UNITED STATES,

                                      Appellee,

                                          v.

                                   ALFRED TRENKLER,

                                Defendant - Appellant.

                                 ____________________

                     APPEAL FROM THE UNITED STATES DISTRICT COURT

                          FOR THE DISTRICT OF MASSACHUSETTS

                       [Hon. Rya W. Zobel, U.S. District Judge]
                                           ___________________

                                 ____________________

                                        Before

                                Torruella, Chief Judge,
                                           ___________
                            Coffin, Senior Circuit Judge,
                                    ____________________
                              and Stahl, Circuit Judge.
                                         _____________

                                 ____________________

            Morris M.  Goldings with whom  Amy J. Axelrod, R.  David Beck, and
            ___________________            ______________  ______________
        Mahoney, Hawkes & Goldings were on brief for appellant.
        __________________________
            Paul  V. Kelly, Assistant  United States Attorney, with whom Frank
            ______________                                               _____
        A. Libby, Jr., Assistant  United States Attorney and Donald  K. Stern,
        _____________                                        ________________
        United States Attorney, were on brief for appellee.

                                 ____________________

                                    July 18, 1995
                                 ____________________

                      STAHL, Circuit Judge.  Following a lengthy criminal
                      STAHL, Circuit Judge.
                             _____________

            trial, a jury convicted  defendant Alfred Trenkler of various

            charges  stemming  from  a  bomb  explosion  in   Roslindale,

            Massachusetts ("the Roslindale  bomb").  On  appeal, Trenkler

            challenges  the  admission  of   evidence  relating  to   his

            participation  in a  prior bombing  that occurred  five years

            earlier  in  Quincy,   Massachusetts  ("the  Quincy   bomb").

            Trenkler  also  assigns  error  to  two  evidentiary  rulings

            admitting evidence  derived  from a  computer  database  that

            purported to  establish that  Trenkler built both  the Quincy

            and  the Roslindale bombs and several out-of-court statements

            made by a fellow  participant in the bombing.   After careful

            review, we affirm.

                                          I.
                                          I.
                                          __

                                      Background
                                      Background
                                      __________

                      On  October  28,  1991,  a  bomb  exploded  at  the

            Roslindale home of Thomas L.  Shay ("Shay Sr."), killing  one

            Boston police officer and severely injuring another.  The two

            officers, members of the Boston Police Department Bomb Squad,

            had been  dispatched  to Shay  Sr.'s  home to  investigate  a

            suspicious object located  in Shay Sr.'s driveway.   Shay Sr.

            had  earlier  reported that,  while  backing  his 1986  Buick

            Century  into the street the day  before, he had heard a loud

            noise   emanating  from   beneath   the  floorboard   of  his

                                         -2-
                                          2

            automobile.  Shay Sr. added that,  subsequently, he found the

            suspicious object resting near the crest of his driveway.

                      Following  the  explosion, a  massive investigation

            ensued involving  a variety of federal, state  and local law-

            enforcement agencies.   On June 24,  1993, this investigation

            culminated  with  the  return  of  a  three-count  indictment

            charging Trenkler and Thomas A. Shay ("Shay Jr."), Shay Sr.'s

            son,   with  responsibility  for   the  Roslindale  bombing.1

            Trenkler  filed  a  successful  severance  motion,   and  the

            government tried the two defendants separately.  Shay Jr. was

            tried first, and a jury convicted him on counts of conspiracy

            and   malicious   destruction   of  property   by   means  of

            explosives.2

                      At Trenkler's trial, the thrust of the government's

            case was that Trenkler had built the Roslindale bomb for Shay

            Jr.  to  use against  his  father.   To  establish Trenkler's

            identity as the builder of the bomb,  the government offered,

            inter alia, evidence that Trenkler had previously constructed
            _____ ____

                                
            ____________________

            1.  The  June  24,   1993,  indictment  specifically  charged
            Trenkler and  Shay  Jr. with  conspiracy,  18 U.S.C.     371;
            receipt of explosive materials with knowledge and intent that
            they  would be used to kill, injure and intimidate, and cause
            damage to real and personal property, 18 U.S.C.   844(d); and
            malicious destruction of property  by means of explosives; 18
            U.S.C.    844(i).    The indictment  superseded a  five-count
            indictment initially returned against  Trenkler and Shay  Jr.
            on December 16, 1992.

            2.  The  district  court  sentenced  Shay  Jr.  to concurrent
            sentences of 188 and 60 months.  

                                         -3-
                                          3

            a remote-control  device, the Quincy bomb,  which exploded in

            Quincy, Massachusetts,  in  1986.   The government  contended

            that unique similarities in design, choice of components, and

            overall modus  operandi between  the two bombs  compelled the
                    _____  ________

            conclusion that Trenkler had designed and built both devices.

            Prior  to trial,  the  government filed  a  motion in  limine
                                                               __  ______

            seeking to admit the "similarity" evidence.  Following a day-

            long  evidentiary  hearing,  the  district  court  ruled  the

            evidence  admissible, finding  that  it was  relevant on  the

            issues of  identity, skill, knowledge, and  intent.  Although

            Trenkler  did not testify at trial, his counsel stipulated at

            the evidentiary  hearing that  Trenkler had built  the Quincy

            bomb.3  

            1986 Quincy Bomb
            1986 Quincy Bomb
            ________________

                      Trenkler constructed the Quincy  bomb in 1986 for a

            friend,  Donna Shea.   At  the time,  Shea was involved  in a

            dispute  with the owners of  the Capeway Fish  Market and she

            wanted the bomb to use as a means to intimidate them.  At her

            request, Trenkler assembled a remote-control, radio-activated

            explosive device.    The device  was  later attached  to  the

            undercarriage of a truck belonging to the Capeway Fish Market

                                
            ____________________

            3.  During  the  original  1986 investigation  of  the Quincy
            bombing, Trenkler admitted building  the bomb.  In  1987, the
            Commonwealth   of   Massachusetts  brought   charges  against
            Trenkler for his  involvement in the Quincy bombing,  but the
            charges were dismissed.

                                         -4-
                                          4

            and detonated in the middle of the night.  The resulting bomb

            blast caused no injuries and little property damage.

                      In building  the Quincy bomb, Trenkler  used as the

            explosive  material  a  military  flash  simulator  typically

            utilized to  mimic gunfire in  combat exercises.   To provide

            remote-control  capabilities,  Trenkler  employed   a  radio-

            receiver  he  had removed  from a  small  toy car.   Trenkler

            wrapped the bomb  in duct  tape and attached  a large  donut-

            shaped speaker magnet  to enable  the bomb to  adhere to  the

            undercarriage of  the truck.  Other  components Trenkler used

            included a  "double throw" toggle switch,  four AA batteries,

            two six-volt  batteries, an  electric relay, solder,  various

            wires, and a slide switch.

                      Testimony  at  trial   established  that   Trenkler

            purchased some  of the  electrical components for  the Quincy

            bomb from a  Radio Shack  store.  On  one occasion,  Trenkler

            sought to obtain needed  components by sending Shea's eleven-

            year-old nephew into a Radio Shack store with a list of items

            to purchase while Trenkler  remained waiting outside.  Shea's

            nephew, however, was  unable to  find all of  the items,  and

            Trenkler eventually came into the store to assist him.  

            1991 Roslindale Bomb
            1991 Roslindale Bomb
            ____________________

                      The  government contended  that Trenkler  built the

            Roslindale  bomb  at  Shay  Jr.'s  request.    At trial,  the

            government  offered  evidence  about Trenkler's  relationship

                                         -5-
                                          5

            with Shay  Jr., dating back  at least two years  prior to the

            Roslindale bombing.  Several witnesses,  including Trenkler's

            business  partner,  reported  seeing  the  two  together   on

            different  occasions in  1990 and 1991.   Shay  Jr.'s address

            book included an entry for Trenkler listing his current pager

            number.   Moreover, Trenkler's roommate  at the  time of  the

            Roslindale  bombing  testified  that,  during  September  and

            October of 1991, Shay Jr. left several voice-mail messages on

            the pager for Trenkler.    

                      Testimony  from  government investigators  and Shay

            Sr.  established  that  the  Roslindale bomb  was  a  remote-

            control,  radio-activated  device  with  an  explosive  force

            supplied  by two or three sticks of dynamite connected to two

            electrical blasting caps.  A black wooden box weighing two or

            three pounds and measuring approximately eight- to ten-inches

            long, five- to  six-inches wide and  one- to two-inches  deep

            housed  the bomb.   A large  donut-shaped magnet  and several

            smaller round magnets attached to the box were used to secure

            the  device to the underside of Shay Sr.'s automobile.  Other

            components used in the construction of the bomb included duct

            tape, a "single throw" toggle switch, four AA batteries, five

            nine-volt batteries, a Futaba radio receiver, solder, various

            wires, and a slide switch.  

                      According to the government's experts and Shay Sr.,

            the bomb was originally attached to the undercarriage of Shay

                                         -6-
                                          6

            Sr.'s  automobile directly  beneath the  driver's seat.   The

            government's explosives expert testified that if the bomb had

            exploded while still  attached to the car,  it probably would

            have  killed or  at  least seriously  injured any  individual

            sitting in the driver's seat.

                      The  government also  asserted  that Trenkler  used

            Shay Jr. to  purchase the electronic  components used in  the

            bomb.     In  support  of  this   assertion,  the  government

            introduced a sales receipt  for a toggle switch purchased  in

            October 1991 at a Radio Shack store located across the street

            from  where Trenkler, at the time, was installing a satellite

            dish.4    Agents from  the  Bureau  of Alcohol,  Tobacco  and

            Firearms ("ATF") recovered from  the debris of the Roslindale

            bomb  a  switch identical  to the  one  purchased.   Shay Jr.

            admitted  purchasing  the switch  during  a  taped television

            interview, portions  of  which the  government introduced  at

            trial.5    Furthermore,  a  sales clerk  at  the  Radio Shack

            testified that,  prior to  purchasing the switch,  the person

                                
            ____________________

            4.  Trenkler has an extensive  background in electronics.  At
            the time of the Roslindale bomb, he operated his own business
            installing satellite dishes and other electronic equipment.

            5.  The Radio Shack sales receipt has the  letters "sahy jyt"
            printed in a space  for the customer's address and  lists the
            customer's  "ID"   number  (the  last  four   digits  of  the
            customer's phone number) as "3780."  The government maintains
            that this corroborates Shay Jr.'s statement that he purchased
            components for the bomb because "sahy" is a  transposition of
            "Shay" and "3780" is a transposition of "7380," the last four
            digits of Shay Sr.'s phone number. 

                                         -7-
                                          7

            who bought it had  browsed in the store for  several minutes,

            appearing  to shop  for items written  on a list.   The sales

            clerk also testified that he  recalled seeing Trenkler in the

            store on two or three occasions during the fall of 1991.

                      Both the government and Trenkler elicited testimony

            from  their  respective  explosives  experts  explaining  the

            similarities  and differences  between the  two bombs.   Both

            experts   testified  at  length   concerning  the  electronic

            designs,  the   choice  of  components  and   the  method  of

            construction.   The government's  expert opined that  the two

            incidents shared  many  similar traits  and  characteristics,

            evincing  the "signature" of a single bomb maker.  He further

            stated that he had no doubt "whatsoever" that the same person

            built  both bombs.   Trenkler's  expert, on  the other  hand,

            stated that too many dissimilarities existed to conclude that

            the  same  person built  both  bombs.   Moreover,  Trenkler's

            expert testified  that the similarities  that existed  lacked

            sufficient distinguishing qualities to identify the two bombs

            as the handiwork of a specific individual.

            EXIS Computer Database Evidence
            EXIS Computer Database Evidence
            _______________________________

                      To support  the inference that Trenkler  built both

            bombs, the government offered  testimony both at the pretrial

            hearing and at trial concerning information retrieved from an

            ATF  computer database  of  explosives and  arson  incidents.

            Stephen Scheid, an Intelligence Research Specialist with ATF,

                                         -8-
                                          8

            testified  that  the   database,  known  as  EXIS,   contains

            information taken  from reports  submitted to ATF  by various

            federal, state  and local law-enforcement  agencies.   Scheid

            further testified that he had been personally responsible for

            maintaining the database  since 1977.  Scheid  stated that he

            reviews  submitted   incident  reports,  culling   from  them

            information describing the characteristics of each bombing or

            arson  episode.    Scheid  added  that  he then  encodes  the

            extracted  information on a  standardized worksheet, which he

            or  a data-entry person in turn uses to enter the information

            into the database.

                      Scheid  testified   that,  through  the  use  of  a

            computer  program, he  then produces  investigatory leads  by

            retrieving  all incidents  entered in  the database  that are

            listed as possessing a specific  component or characteristic.

            Scheid  further testified that, in  an effort to identify the

            builder of  the  Roslindale bomb,  he performed  a series  of

            computer   queries,  focusing   on  characteristics   of  the

            Roslindale bomb.  This series of inquiries narrowed the field

            of  reported incidents in the database from 40,867 to seven.6

                                
            ____________________

            6.  The computer  queries and  the total number  of resulting
            incidents are listed below.  The queries are successive.

                      All incidents in database       - 40,867

                      Bombings and attempted bombings - 14,252

                      Involving cars and trucks       -  2,504

                                         -9-
                                          9

            The seven remaining  incidents included  both the  Roslindale

            and  Quincy  bombs.    Scheid  stated  that  he  subsequently

            conducted a  manual analysis  of the remaining  incidents and

            was  able  to  identify  several  additional  characteristics

            common to only the Roslindale and Quincy bombs.7

                      Scheid also testified that the report of the Quincy

            bomb did not come to his attention through normal procedures.

            Scheid  did not  receive  information about  the 1986  Quincy

            bomb,  nor enter  any information  pertaining to it  into the

            EXIS database, until after the Roslindale incident in 1991.8

            Other Trial Evidence   
            Other Trial Evidence
            ____________________

                      The government  also offered the testimony of David

            Lindholm to establish that  Trenkler had built the Roslindale

            bomb.    Lindholm  testified  that he  met  Trenkler  at  the

                                
            ____________________

                      Under vehicles                  -    428

                      Remote-control                  -     19

                      Using magnets                   -      7

            7.  Scheid testified that, of  the seven remaining incidents,
            only  the Roslindale  and the  Quincy bomb  were reported  as
            possessing  all  of  the  additional features:    duct  tape,
            soldering,  AA   batteries,  toggle  switches,   and  "round"
            magnets.

            8.  Scheid testified that, in entering information about  the
            Quincy  bombing into the EXIS database, he relied solely on a
            laboratory report prepared in  1986 by investigators from the
            Massachusetts  Department  of Public  Safety.    This report,
            however,  does not state that the Quincy bomb was attached to
            the  underside of the  Capeway truck.  It  only refers to the
            bomb as an "[e]xplosion on truck."  Nevertheless, Scheid used
            "under vehicle" as  one of the computer queries  that matched
            the Quincy and Roslindale bombings.

                                         -10-
                                          10

            Plymouth House of Correction  where they had spent  four days

            incarcerated together in an uncomfortable orientation holding

            cell in December 1992.  Lindholm testified that initially the

            cell had held about forty-four prisoners, but that eventually

            the total number  of prisoners in the cell dwindled to six or

            seven.   Lindholm  added that  he had  numerous conversations

            with  Trenkler over  the  course of  the  four days  as  they

            gradually "bonded"  upon discovering that they  came from the

            same home town and had similar backgrounds.  

                      Lindholm  testified that  he  gave  Trenkler  legal

            advice based on  his own experience as a  criminal defendant.

            Lindholm  acknowledged that  Trenkler initially  asserted his

            innocence and had maintained that he could not understand why

            Shay  Jr. had implicated him in the case.  Lindholm testified

            further that Trenkler later told him that the government knew

            that some of the  components used in the Roslindale  bomb had

            been purchased locally and that, in response, Lindholm opined

            that  the bomber had  been careless not  to have gone  out of

            state.  To  this, Trenkler  agreed and then  stated that  the

            local purchase was "regrettable."

                      In addition,  Lindholm recalled  that at  one point

            during the four  days they  discussed Trenkler's  involvement

            with the 1986  Quincy bomb.  Lindholm  testified that, during

            this discussion,  Trenkler asserted that  the Roslindale bomb

            was much  more powerful than the  bomb he had built  in 1986.

                                         -11-
                                          11

            Ultimately, Lindholm stated  that Trenkler admitted  building

            the Roslindale bomb, testifying that:

                      [Lindholm:]    At  one point  he  stated,
                      ["W]ell, even  if I  did build a  bomb, I
                      did not place it on the car.["]

                      [Government:]  What happened next?

                      [Lindholm:]  Then he  paused for a moment
                      and  said, ["S]o,  I built  the bomb.   I
                      built the  bomb.  I don't  deserve to die
                      or spend  the rest  of my life  in prison
                      for building this device.["]

            Lindholm  added further  that Trenkler  "stated that  the two

            bomb  squad  officers  were  foolish and  negligent  for  not

            wearing  body armor at the time that they were examining this

            device, and in  essence that  it served them  right for  what

            happened to them.  It wasn't his fault."  

                      At  the   time  of  trial,  Lindholm   was  serving

            sentences stemming  from convictions on federal  drug and tax

            evasion charges.  Lindholm testified that he had not received

            nor  discussed  receiving  anything  from  the  government in

            return for  his testimony.  On  cross examination, Trenkler's

            counsel  made  only a  minimal  effort  to impeach  Lindholm,

            raising  matters  unrelated  to  his   testimony  implicating

            Trenkler.     Primarily   Trenkler's  counsel   attempted  to

            challenge Lindholm's  assertion that, as a small  boy, he had

            at one  time lived on the same street as Trenkler and to show

            that  Lindholm was  at  the Plymouth  House of  Correction in

            December  1992  in  order   to  provide  information  to  the

                                         -12-
                                          12

            government  on  other  individuals  with  whom  he  had  been

            involved in past criminal activities.

                      In  addition to  Lindholm's  testimony, ATF  Agents

            Dennis Leahy  and Thomas  D'Ambrosio recounted a  November 6,

            1991, interview  they conducted  with Trenkler shortly  after

            the  bombing.    During  this  interview,  Trenkler  admitted

            building  the  Quincy bomb  and  sketched  a circuit  diagram

            describing  it.   After making  the sketch,  Agent D'Ambrosio

            asked Trenkler how the  diagram would differ if Trenkler  had

            used dynamite like that  utilized in the Roslindale incident.

            Both  agents testified  that, in  response to  this question,

            Trenkler drew a second diagram,  which featured two sticks of

            dynamite  connected to  two electrical  blasting caps.   Both

            agents  added that  they  were surprised  when  they saw  the

            diagram because the use of two electrical blasting caps was a

            distinctive feature of  the Roslindale bomb that, at the time

            of the interview, had not been disclosed  to the public.9  At

            trial,  Leahy also  related other  conversations he  had with

            Trenkler in  which Trenkler  conveyed a working  knowledge of

            dynamite and electrical blasting caps.

                      Leahy further testified  about a statement Trenkler

            made to  him at the ATF  offices on February 4,  1992.  Leahy

                                
            ____________________

            9.  Although the  agents  conducted the  interview  during  a
            search of Trenkler's place of business (to which Trenkler had
            consented), neither agent attempted  to keep the drawing and,
            consequently, it was not produced at trial.     

                                         -13-
                                          13

            explained  that Trenkler had come  to the offices  on his own

            accord to pick up  previously-seized business records.  Leahy

            stated that,  during his visit,  Trenkler engaged Leahy  in a

            long  discussion,  lasting more  than  two  hours, about  the

            course of the investigation.  According to Leahy's testimony,

            after  Leahy had  ended  the  discussion, Trenkler  announced

            arrogantly upon leaving the  ATF offices that "If we  did it,

            then only we know about it.  How will you ever find out . . .

            if neither one of us talk[]?"        

                      The jury returned a guilty verdict on all counts of

            the indictment.   Subsequently, the district  court sentenced

            Trenkler  to concurrent  terms  of life  imprisonment on  the

            counts  of  receipt  of  explosive  materials  and  attempted

            malicious destruction of property  by means of explosives and

            sixty months  on  the  count  of conspiracy.    Trenkler  now

            appeals.    

                                         II.
                                         II.
                                         ___

                                      Discussion
                                      Discussion
                                      __________

                      On appeal,  Trenkler assigns error to the admission

            of the  Quincy bomb  evidence, contending primarily  that the

            incident was not sufficiently  similar to the Roslindale bomb

            to be relevant on the issue of identity, and to the admission

            of the  EXIS  database-derived evidence  that the  government

            used  to prove  the similarity  of the  two bombs.   Trenkler

            additionally  argues  that  the  district  court  erroneously

                                         -14-
                                          14

            admitted several out-of-court statements made by Shay Jr.  We

            discuss each argument in turn.10

            A.  Quincy Bombing Evidence
            ___________________________

                      We   begin  with  Trenkler's  contention  that  the

            district court erred in admitting  the evidence of the Quincy

            bombing.

                      1.  Fed. R. Evid. 404(b):  Other Act Evidence
                      _____________________________________________

                      In  general,  Rule 404(b)11  proscribes the  use of

            other bad-act evidence solely to establish that the defendant

            has a  propensity towards  criminal behavior.   Rule 404(b)'s

            proscription, however, is not absolute:  the rule permits the

                                
            ____________________

            10.  Trenkler   also  raises   the  issue   of  prosecutorial
            misconduct.     Trenkler  contends   that  counsel  for   the
            government  intentionally  made inflammatory  remarks  in the
            government's  opening  statement  and  introduced  prohibited
            other-act  evidence  in   contravention  of   representations
            previously made to  the district court.  We find  no merit in
            these contentions.   

            11.  Fed. R. Evid. 404(b) provides:

                      (b)  Other   Crimes,  Wrongs,   or  Acts.
                      Evidence of other crimes, wrongs, or acts
                      is not admissible  to prove the character
                      of a  person in  order to show  action in
                      conformity therewith.   It may,  however,
                      be admissible for other purposes, such as
                      proof  of  motive,  opportunity,  intent,
                      preparation,  plan,  knowledge, identity,
                      or  absence  of   mistake  or   accident,
                      provided   that   upon  request   by  the
                      accused,  the  prosecution in  a criminal
                      case shall provide  reasonable notice  in
                      advance of  trial, or during trial if the
                      court  excuses  pretrial  notice on  good
                      cause shown, of the general nature of any
                      such evidence it intends to  introduce at
                      trial.

                                         -15-
                                          15

            use of such evidence if it bears on a material  issue such as

            motive,  knowledge or  identity.   In  this Circuit,  we have

            adopted a two-part test  for determining the admissibility of

            Rule 404(b)  evidence.  E.g., United States  v. Williams, 985
                                    ____  _____________     ________

            F.2d 634, 637  (1st Cir.  1993).  First,  the district  court

            must  determine  whether  the   evidence  has  some  "special

            relevance"  independent  of  its   tendency  simply  to  show

            criminal propensity.  E.g., United  States v. Guyon, 27  F.3d
                                  ____  ______________    _____

            723,  728 (1st  Cir.  1994).   Second,  if the  evidence  has

            "special relevance" on a material issue,  the court must then

            carefully conduct a  Rule 40312 analysis to determine  if the

            probative  value  of  the   evidence  is  not   substantially

            outweighed by the danger of unfair prejudice.  Williams,  985
                                                           ________

            F.2d  at 637.  As with most evidentiary rulings, the district

            court has considerable leeway in determining whether to admit

            or exclude Rule  404(b) evidence.  Accordingly, we review its

            decision  only under the lens  of abuse of  discretion.  Id.;
                                                                     ___

            see  also United  States v.  Fields, 871  F.2d 188,  196 (1st
            ___  ____ ______________     ______

            Cir.), cert. denied, 493 U.S. 955 (1989).   
                   _____ ______

                                
            ____________________

            12.  Fed. R. Evid. 403 provides:

                      Although   relevant,   evidence  may   be
                      excluded  if  its   probative  value   is
                      substantially outweighed by the danger of
                      unfair   prejudice,   confusion  of   the
                      issues,  or  misleading the  jury,  or by
                      considerations of undue  delay, waste  of
                      time,   or   needless   presentation   of
                      cumulative evidence.

                                         -16-
                                          16

                      2.  Identity
                      ____________

                      The  government offered the  evidence of the Quincy

            bomb, which  Trenkler admitted building,  primarily to  prove

            that Trenkler also built the Roslindale bomb.  The government

            contends that  the evidence of  the Quincy bomb  has "special

            relevance"  on the  issue  of identity  because the  numerous

            similarities  surrounding the Quincy and Roslindale incidents

            compel  the conclusion  that the  same individual  built both

            bombs.  Trenkler, on  the other hand, argues that  the Quincy

            incident is too  dissimilar to  be relevant on  the issue  of

            identity,  and even  if it  has some  relevance, the  risk of

            unfair prejudice  that it  poses far outweighs  its probative

            value.  We  agree with  the government that  the Quincy  bomb

            evidence has "special relevance" on the issue of identity and

            that  the  district  court  did not  abuse  its  considerable

            discretion in admitting it.

                           a.  Rule 404(b) Evidence:  Special Relevance
                           ____________________________________________

                      When,  as in  this  case, Rule  404(b) evidence  is

            offered because it  has "special relevance"  on the issue  of

            identity, we have required, as a prerequisite to admission, a

            showing that there exists a high degree of similarity between

            the other  act and the charged  crime.  See United  States v.
                                                    ___ ______________

            Ingraham, 832 F.2d 229, 231-33 (1987), cert. denied, 486 U.S.
            ________                               _____ ______

            1009 (1988).  Indeed, the proponent must demonstrate that the

            two acts  exhibit a  commonality  of distinguishing  features

                                         -17-
                                          17

            sufficient  to  earmark them  as  the handiwork  of  the same

            individual.   Id.  at  231.    This  preliminary  showing  is
                          ___

            necessary because 

                      [a] defendant cannot be identified as the
                      perpetrator  of  the  charged act  simply
                      because  he has at  other times committed
                      the same commonplace variety  of criminal
                      act except by  reference to the forbidden
                      inference  of  propensity.   The question
                      for  the  court[,  therefore,   must  be]
                      whether  the characteristics  relied upon
                      are sufficiently  idiosyncratic to permit
                          ____________  _____________
                      an inference of  pattern for purposes  of
                      proof.
              
            United States v. Pisari, 636 F.2d 855, 858-59 (1st Cir. 1981)
            _____________    ______

            (internal quotations and citations omitted) (emphasis added).

                      Resolving  whether the  prior  act is  sufficiently

            similar to the charged offense to have "special relevance" on

            the issue  of identity, however,  is essentially an  issue of

            "preliminary"  or "conditional"  fact.   In other  words, the

            prior act has no tendency to prove the perpetrator's identity

            -- i.e., it is not relevant -- unless the proponent can first
               ____

            establish  the  conditional  fact:   that  the  two  acts are

            sufficiently idiosyncratic to support the inference that they

            are  the handiwork of the same individual.  The admissibility

            of  evidence whose  relevance turns  on the  resolution of  a

            conditional  fact is governed by  Fed. R. Evid.  104(b).  See
                                                                      ___

            Huddleston  v. United States, 485 U.S. 681, 689 (1988).  Rule
            __________     _____________

            104(b) provides, "When the relevancy of evidence depends upon

            the fulfillment of a condition of fact, the court shall admit

                                         -18-
                                          18

            it  upon,  or  subject   to,  the  introduction  of  evidence

            sufficient to  support a  finding of the  fulfillment of  the

            condition."  Fed. R. Evid. 104(b).  Moreover,

                      [i]n  determining whether  the Government
                      has  introduced  sufficient  evidence  to
                      meet Rule 104(b), the trial court neither
                      weighs  credibility  nor makes  a finding
                      that  the  Government   has  proved   the
                      conditional  fact  by a  preponderance of
                      the  evidence.  The court simply examines
                      all  the evidence in the case and decides
                      whether  the  jury could  reasonably find
                      the  conditional   fact  .   .  .  by   a
                      preponderance of the evidence.

            Huddleston, 485  U.S. at 690.   Thus, as  here, when a  party
            __________

            seeks to  admit Rule  404(b) evidence to  establish identity,

            the district court must condition  its admission on a showing

            that the  shared characteristics  of  the other  act and  the

            charged   offense  are  sufficiently   idiosyncratic  that  a

            reasonable jury could find  it more likely than not  that the

            same person performed them both.13  

                                
            ____________________

            13.  Huddleston involved  the use of Rule  404(b) evidence to
                 __________
            prove knowledge in a case where the petitioner, charged  with
            the knowing possession of stolen video tapes, claimed that he
            did  not know the  tapes were stolen.   485 U.S.  at 683.  In
            order to prove knowledge, the  government introduced evidence
            of  the  petitioner's  previous   involvement  in  sales   of
            allegedly stolen television sets.  The Supreme Court rejected
            the   petitioner's  contention  that,  before  admitting  the
            evidence,  the   district  court  was  required   to  make  a
            preliminary finding  that the government had  proven that the
            television sets were in fact stolen.  Id. at 687.
                                                  ___
                      The Court stated that  "Rule 404(b) . . .  protects
            against the introduction of  extrinsic act evidence when that
            evidence  is  offered solely  to prove  character.   The text
            contains no intimation, however, that any preliminary showing
            is necessary  before such  evidence may be  introduced for  a
            proper purpose."    Id.  at 687-88.    The  Court  continued,
                                ___

                                         -19-
                                          19

                      Trenkler  contends that  the array  of similarities

            between   the  two  incidents  amounts  to  no  more  than  a

            collection of "prosaic commonalit[ies that] cannot give  rise

            to an inference  that the  same person was  involved in  both

            acts  without reference  to  propensity."   United States  v.
                                                        _____________

            Garcia-Rosa, 876 F.2d 209, 225 (1st Cir. 1989), cert. denied,
            ___________                                     _____ ______

            493 U.S. 1030, cert. granted and vacated on other grounds sub
                           _____ _______ ___ _______ __ _____ _______ ___

            nom., Rivera-Feliciano v. United States, 498 U.S. 954 (1990).
            ____  ________________    _____________

            However,  in  resolving  whether  the  evidence  supports  an

            inference   that  the   two   incidents   are   "sufficiently

            idiosyncratic," we have cautioned that "an exact match is not

            necessary."  Ingraham, 832 F.2d at 232.  The  test must focus
                         ________

            on  the  "totality  of   the  comparison,"  demanding  not  a

            "facsimile or exact replica"  but rather the "`conjunction of

                                
            ____________________

            stating,  "If offered for such a proper purpose, the evidence
            is subject  only to general strictures limiting admissibility
            such as Rules 402 and 403."  Id. at 688.
                                         ___
                      The Court  then stated  that evidence of  the prior
            sales  was  relevant  for   the  proper  purpose  of  proving
            knowledge only  if the jury  could find the  preliminary fact
            that the televisions  were stolen.   Id. at 689.   Thus,  the
                                                 ___
            Court held  that Rule 104(b) controlled  the admissibility of
            the evidence.  Id.
                           ___
                      Though   the  issue  here   arises  in  a  slightly
            different  context, we  think  that  Huddleston provides  the
                                                 __________
            appropriate framework for our analysis.  Here, the government
            offered the Quincy bomb evidence  for the proper Rule  404(b)
            purpose of identity.  The relevance of the Quincy bomb on the
            issue of  identity turns, however, on the factual question of
            whether   the  Roslindale   and  the   Quincy   bombings  are
            sufficiently similar to earmark them as  the handiwork of the
            same individual.  This is analogous to whether the television
            sets in Huddleston were stolen, and, accordingly, Rule 104(b)
                    __________
            sets the framework for admissibility. 

                                         -20-
                                          20

            several identifying characteristics  or the presence of  some
                                                 __

            highly distinctive quality.'"  Id. at 232-33 (quoting Pisari,
                                           ___                    ______

            636  F.2d at 859) (emphasis added); see also United States v.
                                                ___ ____ _____________

            Myers,  550 F.2d 1036, 1045  (5th Cir. 1977)  ("[A] number of
            _____

            common  features of lesser  uniqueness, although insufficient

            to  generate a  strong  inference of  identity if  considered

            separately,  may  be  of  significant  probative  value  when

            considered together.").  In this  case, we think the  balance

            of  the  evidence  tilts  sufficiently  towards admission  to

            satisfy  the   first  step  of  the   Rule  404(b)  analysis.

            Accordingly, we believe that the district court did not abuse

            its discretion  in determining that the numerous similarities

            in components,  design, and  technique of  assembly, combined

            with  the  similar  modus   operandi  and  the  closeness  of
                                _____   ________

            geographic  proximity between  the  two events,  sufficiently

            support the inference that the same person built both bombs.

                      We begin by noting that the government's explosives

            expert,  Thomas Waskom,  testified that  his analysis  of the

            similarities shared by  the two  incidents left  him with  no

            doubt "whatsoever" that the same individual built both bombs.

            Our own review of  the record reveals that the  two bombs did

            indeed   share   a   number   of   similar   components   and

            characteristics.   Both bombs  were remote-controlled, radio-

            activated, electronic explosive devices.  Both were  homemade

            mechanisms,  comprising,  in  general, electronic  components

                                         -21-
                                          21

            easily  purchased at a hobby store.  Both had similar, though

            not  identical,  firing  and  fusing  circuits with  separate

            battery  power supplies for each.  Both had switches in their

            fusing  circuits  to  disconnect  the radio  receivers.    To

            energize  their  respective  radio  receivers,  both  devices

            utilized  similar  power  supplies,  consisting  of  four  AA

            batteries.   Both  employed many  similar components  such as

            batteries,  duct  tape,  toggle  switches,  radio  receivers,

            antennas,  solder, electrical tape,  and large  round speaker

            magnets.   Moreover,  both used  a distinctive  method (i.e.,
                                                                    ____

            twisting, soldering, and taping)  to connect some, though not

            all,  of the  wires  used.14   Though we  hardly find  any of

            these factors  by themselves to be  "highly distinctive," the

            coalescence  of them  is fairly  persuasive.15   Indeed, even

                                
            ____________________
            14.  Though  it is unclear from a close reading of the record
            just  how  many  of the  wires  in  each  bomb employed  this
            connection method,  it is  apparent that  at least  some did.
            More interestingly,  we note that, before  learning that both
            bombs had wires that were joined in this fashion,  Trenkler's
            explosives expert  stated that such a method is a "singularly
            unique method[] of assembly  which individual bomb makers are
            very likely to repeat."

            15.  On the other hand,  Trenkler argues that the differences
            between  the two  bombs are  more significant.   Some  of the
            differences that Trenkler cites include: 

                     Roslindale Bomb                   Quincy Bomb

             Two or three sticks of          Military flash simulator used
             dynamite rewrapped in a         which produced only minor
             magazine page and electrical    damage
             blasting caps which killed one
             officer and severely injured
             another                     -22-
                                          22

            Trenkler's  expert  witness, Denny  Kline,  testified  at the

            pretrial hearing that, in light of these similarities, "there

            is  a  possibility, a  probability,  that  maybe there  is  a
                                   ___________               _____  __  _

            connection between the maker of these two bombs."   (Emphasis
            __________

            added.)

                      Moreover,  we note  that, in  refusing to  conclude

            "beyond  a reasonable  doubt"16  that the  same person  built

            both bombs, Trenkler's expert  Kline eschewed reliance on any

            factors except  the physical evidence.   The appropriate test

            for sufficient similarity, however, is not so limited.  "[I]n

            assessing the sufficiency of  the evidence under Rule 104(b),

            the trial court  must consider all evidence  presented to the
                                           ___

            jury."  Huddleston, 485 U.S. at 690-91 (emphasis added).  
                    __________

                      Accordingly,  we  believe   some  significance   is

            properly attributed  to the  simple fact that  both incidents

                                
            ____________________
                                
             Futaba remote control system    Radio receiver taken from toy
             which used a small electrical   car
             servo motor                      
             "Single throw" toggle switch    Relay allowed power to be sent
             used to send power to dynamite  to explosives; "double throw"
                                             toggle switch used as safety

             Five nine-volt batteries        Two six-volt batteries
             provided power to firing        supplied power to firing
             system                          system

             Device was housed in a black    Device was wrapped in silver
             wooden box                      duct tape

            16.  As the district court correctly noted in its ruling, the
            government is not required  to establish "beyond a reasonable
            doubt"  that  the  same person  built  the  two  bombs.   See
                                                                      ___
            Huddleston, 485 U.S. at 690.
            __________

                                         -23-
                                          23

            are  bombings.  A bombing, in  and of itself, is, arguably, a

            fairly distinctive  method  for intimidating  or  killing  an

            individual.  Cf. United States v. Patterson, 20 F.3d 809, 813
                         ___ _____________    _________

            (10th Cir. 1994)  (in a hijacking  case, uniqueness of  crime

            itself has  significance in Rule 404(b) similarity analysis),

            cert. denied, 115 S. Ct. 128 (1994);  Pisari, 636 F.2d at 858
            _____ ______                          ______

            ("[M]uch more  is demanded than the  mere repeated commission

            of crimes of the  same class, such as repeated  burglaries or

            thefts.  The device  used must be so unusual  and distinctive
                     ___ ______  ____ ____ __ __ _______  ___ ___________

            as  to  be  like  a  signature."  (quotations  and  citations
            __  __  __  ____  _  _________

            omitted)).   In addition, both incidents  involved not simply

            bombs, but remote-control bombs  that were placed  underneath

            automotive vehicles.  

                      In both  instances, the bombs were  constructed and

            used to benefit a friend of the builder.  Trenkler  built the

            Quincy bomb for Donna Shea to use to intimidate the owners of

            the  Capeway  Fish Market,  and  the  evidence supported  the

            inference that the person who constructed the Roslindale bomb

            built  it  for   Shay  Jr.   to  use   against  his   father.

            Furthermore,  in  both  instances the  builder  attempted  to

            conceal  his or her participation  by using a  third party to

            purchase  the  electronic components  used  in  the explosive

            device.   In 1986, Trenkler initially waited in his car while

            sending Donna Shea's nephew into the electronics store with a

            list  to  purchase the  needed  components.   Similarly,  the

                                         -24-
                                          24

            evidence  supports  the inference  that  the  builder of  the

            Roslindale  bomb  used  Shay   Jr.  to  purchase  the  needed

            components.   Finally, the  fact that both  bombings occurred

            within a relatively close  geographic proximity must be given

            some weight in the analysis.  

                      In United States v. Pisari, 636 F.2d 855  (1st Cir.
                         _____________    ______

            1981),  we reversed  the district  court's decision  to admit

            evidence  of a prior robbery solely on the issue of identity,

            where the  only similarity between it and the charged offense

            was  that a knife was  used.  Similarly,  in Garcia-Rosa, 876
                                                         ___________

            F.2d at 224-25,  we refused  to sanction the  admission of  a

            prior drug  transaction where the only characteristic linking

            it to  the charged drug deal was  the characteristic exchange

            of a sample of drugs  prior to the sale.  In  Garcia-Rosa, we
                                                          ___________

            held that a single "prosaic commonality" was insufficient "to

            give rise to an  inference that the same person  was involved

            in both acts without  reference to propensity."  Id.  at 225.
                                                             ___

            See  also United States v. Benedetto, 571 F.2d 1246, 1259 (2d
            ___  ____ _____________    _________

            Cir.  1978) (no  signature  where  shared  characteristic  is

            merely  "a similar  technique for  receiving  the cash:   the

            passing of folded bills by way of a handshake").  

                      In   the  present  case,  however,  the  government

            presented more than a  single "prosaic commonality."  Indeed,

            the government  propounded a laundry list  of similarities in

            design, component selection,  construction and overall  modus
                                                                    _____

                                         -25-
                                          25

            operandi.    On the  other  hand, Trenkler  offered  a fairly
            ________

            impressive list of differences between the two incidents.  In

            the absence of one or more highly distinctive factors that in

            themselves   point  to  idiosyncracy,  we  must  examine  the

            combination  of all the factors.  Had Trenkler been unable to

            point  to any  significant differences,  we suspect  he would

            have had little chance in establishing an abuse of discretion

            in  allowing the  evidence.   Similarly,  had the  government

            found but  three or four common  characteristics to establish

            sufficient  similarity, we  doubt that  the admission  of the

            evidence  would have been granted or sustained.  Here, in the

            middle,  with  substantial  evidence   on  either  side   and

            conflicting  expert opinions,  could a  reasonable jury  have

            found  it more  likely  than not  that  the same  person  was

            responsible for both bombs?  We think the answer is yes.  See
                                                                      ___

            Ingraham,  832 F.2d at  233 (admitting evidence)("[G]iven the
            ________

            host of  important comparables, the  discrepancies --  though

            themselves  not  unimportant--  go   to  the  weight  of  the

            challenged evidence, not to its admissibility.").17

                                
            ____________________

            17.  As we explain infra  in part II.A., we believe  that the
                               _____
            district court erred in  admitting the EXIS database evidence
            on  the issue of idiosyncratic similarity.  Our review of the
            record, however, convinces us that  the EXIS evidence did not
            weigh  significantly in  the  court's decision  to admit  the
            evidence of the Quincy bomb.  Cf. United States v.  Gallo, 20
                                          ___ _____________     _____
            F.3d  7, 14 (1st Cir. 1994) (abuse of discretion occurs when,
            inter alia, improper factor is accorded significant weight).
            _____ ____

                                         -26-
                                          26

                           b.  Rule 404(b) Evidence:  Probative Value and
                           ______________________________________________

                           Unfair Prejudice
                           ________________

                      Resolving that the district court did not abuse its

            discretion in  determining that  a rational jury  could infer

            that it was more likely than  not that the same person  built

            both bombs, however, does not end the analysis.  We must also

            review  the trial  court's determination  that the  probative

            value of the evidence was not substantially outweighed by the

            risk of unfair prejudice.   Several factors weigh heavily  in

            this  balancing,  such  as  the  government's  need  for  the

            evidence,  see Fields, 871 F.2d at 198 (quoting Fed. R. Evid.
                       ___ ______

            404(b) advisory committee's note),  the strength of  evidence

            establishing the similarity of  the two acts, see Huddleston,
                                                          ___ __________

            485 U.S. at 689 n.6, the inflammatory nature of the evidence,

            and the degree to  which it would promote an  inference based

            solely on  the  defendant's criminal  propensity, see  United
                                                              ___  ______

            States v. Rubio-Estrada, 857 F.2d 845, 851-52 (Torruella, J.,
            ______    _____________

            dissenting) (explaining inherent unfair prejudice in evidence

            of prior bad acts).

                      We believe the district court acted well within its

            broad  discretion  in admitting  the  evidence.   First,  the

            evidence  was  important  to  the  government's  case.    The

            evidence that Trenkler had built the Quincy bomb corroborated

            David  Lindholm's  testimony,  identifying  Trenkler  as  the

            builder  of  the  Roslindale  bomb.    Second,  although  the

                                         -27-
                                          27

            evidence of  similarity could  have been more  compelling, it

            was  nonetheless  substantial:    Indeed,   the  government's

            explosives expert testified that he had no doubt "whatsoever"

            that the same person designed and constructed both bombs.  

                      On the  other hand,  we disagree with  the district

            court  that  the evidence  did not  pose  any risk  of unfair

            prejudice.18   As  with  all "bad  act"  evidence,  there  is

            always some danger that the jury will use the evidence not on

            the narrow point for which it is offered  but rather to infer

            that  the   defendant  has  a   propensity  towards  criminal

            behavior.   Nonetheless,  outside the context  of propensity,

            the evidence  was not unduly  inflammatory.  The  Quincy bomb

            did  not  kill or  injure  any individual  and  caused little

            property damage.  Moreover,  the district court minimized any

            risk of  unfair prejudice  by carefully instructing  the jury

            not  to use  the  evidence of  the  Quincy bombing  to  infer

            Trenkler's  guilt  simply  because  he was  a  bad  person or

            because the  fact he had a built  a bomb in the  past made it

            more likely he had built  the bomb in this case.   In sum, we

            believe  that the district court did not abuse its discretion

            in determining  that the probative  value of the  Quincy bomb

                                
            ____________________

            18.  In ruling  on the  evidence, the district  court stated,
            inter alia, "The  evidence of  the [Quincy]  bomb is  without
            _____ ____
            question prejudicial  in the sense  that it will  likely harm
            the defendant.  That  is not the test, however,  the question
            is whether it is unfairly prejudicial.  It is not."

                                         -28-
                                          28

            evidence  was not  substantially  outweighed by  the risk  of

            unfair prejudice.19  

            B.  EXIS Database Evidence
            __________________________

                      Trenkler  contends that the district court erred in

            admitting under the residual hearsay exception, Fed. R. Evid.

            803(24),20  testimony about the results of  the search of the

                                
            ____________________

            19.  Trenkler also  contends that the  district court  abused
            its discretion in admitting the Quincy bomb evidence to prove
            knowledge,  skill, and intent.  With respect to the issues of
            knowledge  and  skill, we  find  little  merit in  Trenkler's
            argument.   Obviously, the fact that Trenkler had in the past
            built a remote-control bomb has  some relevance on whether he
            possessed  the skill  and  knowledge necessary  to build  the
            Roslindale bomb.  See United States v. Latorre, 922 F.2d 1, 8
                              ___ _____________    _______
            (1st  Cir.   1990),  cert.  denied,  502   U.S.  876  (1991).
                                 _____  ______
            Furthermore, because the evidence was otherwise admissible to
            show  identity, allowing  the government  to use  it to  show
            skill  and  knowledge, posed  no  additional  risk of  unfair
            prejudice.     Trenkler's contention with  respect to  intent
            stands   on  firmer   ground.     We  have   some  difficulty
            comprehending   (and   the   government   does   not  clearly
            articulate) any theory of "special relevance" tending to show
            intent that  does  not  depend  heavily on  an  inference  of
            propensity.  See  United States  v. Lynn, 856  F.2d 430,  436
                         ___  _____________     ____
            (1st  Cir. 1988)  (error to  admit evidence  on  intent where
            inference  depends on propensity).   Nonetheless, because the
            evidence was  properly admitted  to show  identity, knowledge
            and  skill,  any error  in its  admission  to show  intent is
            harmless.   See  Benavente Gomez,  921 F.2d at  386 (harmless
                        ___  _______________
            error if it is "highly probable" the error did not contribute
            to the verdict).

            20.  Fed. R. Evid. 803 provides:

                      The  following are  not  excluded by  the
                      hearsay rule, even  though the  declarant
                      is available as a witness:
                      . . .
                      (24) Other Exceptions
                      (24) Other Exceptions
                           A statement not specifically covered
                      by  any of  the foregoing  exceptions but
                      having      equivalent     circumstantial
                      guarantees  of  trustworthiness,  if  the

                                         -29-
                                          29

            EXIS database.   He maintains that  the district court  erred

            because  the underlying reports  composing the  EXIS database

            lack sufficient guarantees of trustworthiness to fall  within

            the residual  hearsay exception.  We agree  that the district

            court erred  in admitting  the evidence,  but find  the error

            harmless.

                      The government offered  the EXIS-derived  testimony

            as tending  to  show that  the  Roslindale and  Quincy  bombs

            evinced the  signature of a single bomb maker.  Specifically,

            the government  offered it as an  affirmative assertion that,

            out  of  more  than  14,000  bombing  and  attempted  bombing

            incidents,  only the  Roslindale  and  the  Quincy  incidents

            possessed in common all of the queried characteristics.   The

            district court admitted the  EXIS-derived testimony under the

                                
            ____________________

                      court determines that  (A) the  statement
                      is  offered as  evidence  of  a  material
                      fact; (B) the statement is more probative
                      on the point for which it is offered than
                      any  other  evidence which  the proponent
                      can  procure through  reasonable efforts;
                      and (C)  the  general purposes  of  these
                      rules and the  interests of justice  will
                      best  be  served   by  admission  of  the
                      statement  into  evidence.    However,  a
                      statement  may not be admitted under this
                      exception  unless  the  proponent  of  it
                      makes   known   to   the  adverse   party
                      sufficiently in advance  of the trial  or
                      hearing to provide the adverse party with
                      a fair opportunity to prepare to meet it,
                      the  proponent's  intention to  offer the
                      statement  and  the  particulars  of  it,
                      including the  name  and address  of  the
                      declarant.

                                         -30-
                                          30

            residual hearsay exception, finding that it was "sufficiently

            reliable."  In reaching this conclusion, the court noted that

            the  EXIS  database   was  used  and  relied   upon  "by  law

            enforcement authorities on a  regular basis."  The government

            asserts  that the district court did not err in admitting the

            testimony because,  in general,  the underlying  reports were

            "written  objective  reports" summarizing  careful  field and

            laboratory  investigations that  the court  could permissibly

            find  to   be  particularly   worthy  of  belief   such  that

            "adversarialtesting ... wouldaddlittle to[their]reliability."

                      Initially,  it  is  evident  that  whether  or  not

            particular  evidence  may  be  admitted  under  the  residual

            hearsay exception is a fact-specific inquiry committed in the

            first instance to the sound discretion of the district court.

            United  States v.  Doe, 860  F.2d 488,  491 (1st  Cir. 1988),
            ______________     ___

            cert.  denied,  490  U.S.  1049  (1989).    We  accord  great
            _____  ______

            deference to the district court's determination, reviewing it

            only  for an  abuse of  discretion.   E.g., United  States v.
                                                  ____  ______________

            Benavente  Gomez,   921  F.2d  378,  384   (1st  Cir.  1990).
            ________________

            Nevertheless,   we   will   overturn   a   district   court's

            determination if,  upon careful  review, we  are left  with a

            "definite  and firm  conviction that the  court made  a clear

            error of  judgment" in its  decision to admit  the testimony.

            Id. (internal quotations and citations omitted).
            ___

                                         -31-
                                          31

                      Under  the residual hearsay exception, the district

            court  must  determine,  inter  alia,  whether the  proffered
                                     _____  ____

            evidence    possesses     "circumstantial    guarantees    of

            trustworthiness" equivalent to  those possessed by  the other

            listed exceptions to  the hearsay  rule.  See  Fed. R.  Evid.
                                                      ___

            803(24); Polansky v.  CNA Ins.  Co., 852 F.2d  626, 631  (1st
                     ________     _____________

            Cir.  1988);  cf. 2  Kenneth S.  Broun  et al.,  McCormack on
                          ___                                ____________

            Evidence   324,  at 362  (John W. Strong  ed., 4th ed.  1992)
            ________

            (equivalent  guarantees   of  trustworthiness  is   the  most

            important issue).   This trustworthiness  inquiry is  largely

            fact driven, and its focus will vary depending on the context

            in which the issue  arises.  See Brookover v.  Mary Hitchcock
                                         ___ _________     ______________

            Memorial Hosp.,  893 F.2d 411, 420 (1st Cir. 1990).  A court,
            _____________

            however, may consider whether the evidence shares reliability

            factors (e.g.,  personal knowledge,  lack of bias)  common to

            the  other hearsay exceptions, see 2 McCormack   324, at 362-
                                           ___   _________

            4,  and whether the  evidence, but for  a technicality, would

            otherwise come within a specific exception, see United States
                                                        ___ _____________

            v.  Nivica,  887 F.2d  1110, 1126-27  (1st Cir.  1989) (where
                ______

            insufficient foundation  laid  to admit  financial  documents

            under  business records  exception, court  had discretion  to

            admit them under residual  exception), cert. denied, 494 U.S.
                                                   _____ ______

            1005 (1990).  Essentially,  the district court must determine

            whether  the totality  of  the circumstances  surrounding the

            statement  establish its  reliability sufficiently  enough to

                                         -32-
                                          32

            justify  foregoing  the rigors  of in-court  testimony (e.g.,

            live testimony under oath, cross-examination) that ordinarily

            guarantee trustworthiness.   See Michael  H. Graham,  Federal
                                         ___                      _______

            Practice and  Procedure:  Evidence,   6775,  at 737-40 (1992)
            __________________________________

            (courts employ  "ad hoc assessment of  reliability based upon

            the totality  of the surrounding circumstances");  cf. United
                                                               ___ ______

            States v. Ellis, 935  F.2d 385, 394 (1st Cir.)  (citing Idaho
            ______    _____                                         _____

            v.  Wright,   497  U.S.  805,  819   (1990))  (guarantees  of
                ______

            trustworthiness  in  Confrontation  Clause  context  must  be

            established  from the "totality of circumstances" surrounding

            the  making of  the statement),  cert.  denied, 502  U.S. 869
                                             _____  ______

            (1991).

                      Because  we believe  that  the  government  clearly

            failed to establish that  the EXIS-derived evidence possessed

            sufficient "circumstantial guarantees of trustworthiness," we

            hold  that  the  district  court  abused  its  discretion  in

            admitting the evidence.  As  noted above, the district  court

            rested its decision to admit the testimony, at least in part,

            on its finding that law-enforcement agencies  use and rely on

            the database "on a regular  basis."  Though we take no  issue

            with this  narrow finding,  it is  hardly dispositive  on the

            issue of trustworthiness.   That law enforcement  authorities

            rely  on information  culled from  the database  does not,  a
                                                                        _

            fortiori, imbue  that information with  sufficient guarantees
            ________

            of trustworthiness to  warrant admission under  Rule 803(24).

                                         -33-
                                          33

            Indeed, law enforcement authorities often rely on information

            during  their  investigations (e.g.,  polygraph examinations,

            anonymous tips)  that would not necessarily  be admissible as

            evidence.  See  United States v.  Scarborough, 43 F.3d  1021,
                       ___  _____________     ___________

            1026  (6th  Cir.  1994)  (polygraph   examinations  generally

            inadmissible); and Fed R. Evid. 801, 802 (prohibiting hearsay
                           ___

            evidence).  

                      More  to  the  point,  the   government  failed  to

            establish that the reports underlying the  database possessed

            any guarantees  of trustworthiness similar to  those found in

            the  enumerated hearsay  exceptions.   See generally  Fed. R.
                                                   ___ _________

            Evid. 803(1)-(23).  Scheid,  the government's expert on EXIS,

            stated that the database derived from reports submitted by  a

            variety of federal, state and local law enforcement agencies.

            Though Scheid testified extensively on the reliability of the

            procedures he  followed to cull information  from the reports

            and  subsequently  input  it  into  the  EXIS  database,  the

            government   offered   virtually  nothing   establishing  the

            reliability of the underlying reports.  

                      On  cross-examination, Scheid, who  had been solely

            responsible  for EXIS  since  1977, admitted  that no  agency

            outside of the ATF was required by law to send reports to the

            EXIS database  and that  state and local  agencies submitting

            reports were not required to follow any express procedures or

            conform to any specific  standards in collecting or recording

                                         -34-
                                          34

            the reported information.   Indeed, it is far from  clear the

            extent  to  which  information  memorialized in  any  of  the

            reports  derives  from   laboratory  analyses,   on-the-scene

            observations  of police officers, second-hand descriptions of

            the device by layperson witnesses, or some other source.  Cf.
                                                                      ___

            United  States v. Scholle, 553 F.2d  1109, 1123-25 (8th Cir.)
            ______________    _______

            (allowing  printouts  from  Drug  Enforcement  Administration

            ("DEA")  computer  database  where  database  comprised  only

            chemical  analyses performed  at regional  DEA laboratories),

            cert. denied, 434 U.S. 940 (1977). 
            _____ ______

                      Scheid further testified that the submitted reports

            need not be signed, and that nothing required the author of a

            submitted report to have  personal knowledge of its contents,

            see  Fed.  R. Evid.  803  advisory  committee's note  ("In  a
            ___

            hearsay situation,  the declarant  is, of course,  a witness,

            and  neither  this rule  nor  Rule  804  dispenses  with  the

            requirement of  firsthand knowledge."); Fed.  R. Evid. 803(6)

            (business  record must  be  recorded by  or from  information

            supplied by  an individual  with personal knowledge),  or for

            that matter  to  be qualified  as  a bomb  investigator,  see
                                                                      ___

            Mathews v. Ashland  Chem., Inc., 770 F.2d  1303, 1309-10 (5th
            _______    ____________________

            Cir. 1985); 4 Jack B. Weinstein et al., Weinstein's Evidence,
                                                    ____________________

              803(8)[03], at 803-283  ("Questions of the qualification of

            the  expert  can  be  raised  as  one  of  the  circumstances

            indicating  lack  of trustworthiness.");  cf.  Beech Aircraft
                                                      ___  ______________

                                         -35-
                                          35

            Corp.   v.   Rainey,   488   U.S.  153,   167   n.11   (1988)
            _____        ______

            ("investigator's skill or experience" is  factor establishing

            trustworthiness of  government evaluative report).   Finally,

            Scheid admitted that he  employed no procedures for verifying

            or updating  information in the  EXIS database that  had been

            submitted by agencies other than ATF.

                      The underlying reports,  arguably, come closest  to

            falling within  the hearsay exception for  public records and

            reports, Fed. R. Evid.  803(8).  In criminal cases,  however,

            Rule  803(8)  does not  authorize  the  prosecution's use  of

            investigative  reports  that  contain  "matters  observed  by

            police officers  and other law enforcement  personnel,"  Fed.

            R. Evid.  803(8)(B), or  "factual findings resulting  from an

            investigation made pursuant to  an authority granted by law,"

            Fed. R. Evid. 803(8)(C).  See United States v. Arias-Santana,
                                      ___ _____________    _____________

            964  F.2d 1262, 1264 (1st  Cir. 1992) (police reports offered

            by prosecution generally inadmissible); but cf., e.g., United
                                                    ___ ___  ____  ______

            States  v. Brown, 9 F.3d  907, 911-12 (11th  Cir. 1993) (Rule
            ______     _____

            803(8)  does  not  necessarily  prohibit the  use  of  police

            records prepared in a routine non-adversarial setting that do

            not  result from  subjective  investigation and  evaluation),

            cert. denied, 115 S. Ct. 152 (1994).  Moreover, the exception
            _____ ______

            provided by  Rule 803(8)  is further  limited by  the general

            qualification proscribing  the use of public  records if "the

                                         -36-
                                          36

            sources of information or other circumstances indicate a lack

            of trustworthiness."  Fed. R. Evid. 803(8).     

                      We have  noted that Congress  intended the residual

            hearsay  exception  to be  used  "`very rarely,  and  only in

            exceptional circumstances.'"   Benavente  Gomez, 921 F.2d  at
                                           ________________

            384 (quoting S. Rep. No. 1277, 93d Cong. 2d Sess., 20 (1974),

            reprinted in 1974 U.S.C.C.A.N.  7051, 7066); see also Nivica,
            _________ __                                 ___ ____ ______

            887 F.2d at 1127 ("Rule 803(24) should  be used stintingly").

            Moreover,  Congress did  not  intend for  the exception  "`to

            establish a broad license  for trial judges to  admit hearsay

            statements   that  do  not  fall  within  one  of  the  other

            exceptions' or `to authorize  major judicial revisions of the

            hearsay rule.'"  Benavente Gomez, 921 F.2d at 384 (quoting S.
                             _______________

            Rep.  No. 127).    In this  case,  the government  failed  to

            establish  that  the  reports  composing  the  EXIS  database

            possessed  guarantees  of trustworthiness  equivalent  to the

            other  exceptions  to  the  hearsay  rule.   Neither  are  we

            convinced  that the totality of circumstances surrounding the

            reports   adequately  assure   their  reliability   where  no

            standardized procedures were employed in creating the reports

            and  the sources  of  the reported  information are  unknown.

            Finally, we find it significant that the government points us

            to no case  in which it has  successfully (or unsuccessfully)

            sought to  admit EXIS-derived evidence to  prove the identity

            of  a bomb  maker.   Accordingly, we  hold that  the district

                                         -37-
                                          37

            court  abused  its discretion  in admitting  the EXIS-derived

            evidence  under the residual exception to the hearsay rule to

            prove the identity of the builder of the Roslindale bomb.21

                                
            ____________________

            21.  Even putting aside our concerns about the reliability of
            the underlying  reports,  we  remain,  in  general,  somewhat
            troubled  by  the government's  use  of  the evidence.    The
            statement that out of more than  14,000 bombing and attempted
            bombing incidents  in the  EXIS database only  the Roslindale
            and  Quincy  incidents  share   the  eight  specific  queried
            characteristics  (bombings  and attempted  bombings, attached
            under car or truck, remote-control, round magnets, duct tape,
            solder, AA  batteries, toggle switches) is  a fairly powerful
            statement, but perhaps a somewhat misleading one.
                      First,  the   statement  assumes  as   a  necessary
            predicate  that each  of the  more than  14,000 EXIS  entries
            definitively  states  whether  or not  the  explosive  device
            described therein actually  possessed those  characteristics.
            We  have some doubt about the validity of such an assumption.
            In  general,  bomb  reconstruction  strikes us  as  a  rather
            resource-intensive operation.   We can envision circumstances
            (e.g., a blast  causing little  or no injuries  or damage,  a
             ____
            bomb  maker  apprehended before  reconstruction investigation
            complete) where  the investigation  and the  resulting report
            might not be nearly as thorough or complete as in the case of
            _____
            either the Roslindale  or the Quincy  bombs.  Indeed,  during
            the preliminary  hearing both  Scheid and Thomas  Waskom, the
            government's explosives expert, acknowledged that the absence
            of an item, such  as magnets or batteries, from  a post-blast
            report  meant  only that  investigators  did  not recover  or
            identify the item and not that it was not used.
                      Second, without further statistical analysis of the
            database, we  believe the  statement that  out  of more  than
            14,000 incidents  only the Quincy and  Roslindale bombs share
            the  eight queried characteristics is potentially incomplete.
            For  example, by our count,  the EXIS database  entry for the
            Roslindale    incident    lists   approximately    twenty-two
            characteristics  describing that  incident.   Nowhere in  the
            record, however, does the government  explain why it chose to
            focus  on  the specific  characteristics  used  to query  the
            database.  It does not suggest that these characteristics are
            more important in a  bomb-signature analysis than any of  the
            other characteristics not chosen.   Moreover, the  government
            does not offer any  analysis of the significance of  the fact
            that  the  Roslindale  and  the Quincy  incidents  share  the
            queried characteristics.   In other words, though it  is true
            that  only  the  Quincy  incident shares  the  eight  queried

                                         -38-
                                          38

                      Although we agree  with Trenkler that the  district

            court  erred  in  admitting  the  EXIS-derived  evidence,  we

            nonetheless  find  the  error  harmless  beyond  a reasonable

            doubt.22    Initially  we  note  that  substantial  evidence,

            beyond  Trenkler's  participation  in  the   Quincy  bombing,

            supported a  finding that he  had built the  Roslindale bomb.

            Principally, David Lindholm  convincingly testified that,  in

            fact, Trenkler had actually admitted  building the Roslindale

            bomb.   Other  admissions  by Trenkler  made  to various  law

                                
            ____________________

            characteristics with the Roslindale  incident, how many other
            incidents  share some other set of eight (or more than eight)
            characteristics with the Roslindale incident?  
                      Arguably, these  concerns go more to  the weight of
            the evidence  than to its  admissibility.  However,  we point
            them out  here  to underscore  the caution  a district  court
            should  employ  in  allowing  evidence couched  in  terms  of
            numerical probabilities.   Cf.  United States v.  Massey, 594
                                       ___  _____________     ______
            F.2d  676,   679-81  (8th  Cir.   1979)  (testimony   stating
            probability  of  match to  be  one chance  in  4,500 unfairly
            confusing where no foundation for statement provided). 

            22.  In  general, we  review an  evidentiary miscue  only for
            harmless error,  dismissing it  if "we  determine that  it is
            highly probable  that  the error  did not  contribute to  the
            verdict."    Benavente  Gomez,  921  F.2d  at  386  (internal
                         ________________
            quotations and  citations omitted).   In this  case, however,
            Trenkler also contends that the erroneously admitted evidence
            deprived  him of  his  confrontation rights  under the  Sixth
            Amendment,  see  U.S.  Const.  amend  VI  ("In  all  criminal
                        ___
            prosecutions, the accused  shall enjoy the right . .  . to be
            confronted  with  the  witnesses against  him.").    Assuming
            arguendo  that the  admission  of the  EXIS-derived  evidence
            ________
            rises to  the level  of constitutional error,  we accordingly
            employ a  stricter standard,  asking whether we  can consider
            the  error harmless  beyond a  reasonable doubt.   See United
                                                               ___ ______
            States v.  Brennan, 994 F.2d 918,  927 (1st Cir. 1993);   see
            ______     _______                                        ___
            also United States  v. Argentine, 814  F.2d 783, 788-89  (1st
            ____ _____________     _________
            Cir.  1987) (constitutional  errors  may not  be regarded  as
            harmless  if there is a reasonable possibility that the error
            influenced the jury in reaching a verdict).

                                         -39-
                                          39

            enforcement  officers  inferentially corroborated  Lindholm's

            testimony,  specifically Trenkler's sketch  of the Roslindale

            bomb,  drawn shortly  after  the explosion  and conspicuously

            featuring two electrical blasting caps.  Moreover, Trenkler's

            arrogant assertion to Agent  Leahy that, "if we did  it, then

            only we know about it . . . how will you ever find out . .  .

            if neither one of us talk[]?" provided further corroboration.

            Additional support could be  inferred from the ample evidence

            the government adduced  establishing Trenkler's  relationship

            withShayJr.and hisknowledgeofbothelectronics andexplosives.23

                      Furthermore,  the  government  offered   the  EXIS-

            derived  evidence to  prove  that the  Roslindale and  Quincy

            bombs  were so similar that  they evinced the  signature of a

            single bomb  maker, thus,  establishing the relevance  of the

            Quincy bomb evidence on the issue of identity.  Our review of

            the  record,  however,  convinces  us  that the  EXIS-derived

            evidence  was not a  critical factor in  the district court's

            decision to admit the Quincy bomb evidence for the purpose of

            proving  identity.   The  EXIS-derived  evidence  was  merely

            cumulative,  corroborating the testimony  of the government's

            explosives expert  who, after testifying in  detail about the

                                
            ____________________

            23.  We note  with some  concern  our dissenting  colleague's
            suggestion   that,   notwithstanding   Lindholm's   testimony
            (elicited by the  U.S. Attorney) that the  government had not
            offered  or  promised  Lindholm  any  consideration  for  his
            testimony, an  implicit quid pro quo  nonetheless existed for
                                    ____ ___ ___
            his cooperation.  See infra  at 65 n.43.  We find  nothing in
                              ___ _____
            the record to support such an inference.

                                         -40-
                                          40

            similarities between the  two bombs,  stated that  he had  no

            doubt "whatsoever"  that the same person  built both bombs.24

            Moreover, as  discussed supra at  20-26, other circumstantial
                                    _____

            evidence tending  to show that the maker  of each bomb used a

            similar modus operandi (e.g., both  bombs built for a friend,
                    _____ ________  ____

            both  bomb   makers  used  third  party   to  acquire  needed

            components)  independently supported  the inference  that the

            same  person built both  bombs.  Finally,  even putting aside

            whether  the   jury  would  have  found   the  two  incidents

            sufficiently  similar to  prove  identity without  the  EXIS-

            derived evidence,  the jury nonetheless would  have been able

            to consider the fact that Trenkler had designed and built the

            Quincy bomb to prove Trenkler's knowledge and skill.

                      In  sum, while  the admission  of the  EXIS-derived

            evidence would not have been harmless error if the only other

            evidence consisted of the expert's testimony of signature and

            the  evidence establishing Trenkler's  relationship with Shay

            Jr. and  his electrical and explosive  skills, the additional

                                
            ____________________

            24.  Our dissenting colleague correctly notes that, in ruling
            on the  admission of the  Quincy bomb evidence,  the district
            court stated that it was "adding" the statistical evidence to
            the expert's testimony.   But we  differ from his  conclusion
            that  it is  "plain" that  the district  court relied  on the
            EXIS-derived  evidence  to  form  "the  critical  final  link
            between  the  two devices,"  see infra  at  55.   Indeed, the
                                         ___ _____
            court's discussion focuses entirely on  the expert testimony,
            with  only the  passing  reference at  the  end to  the  EXIS
            system.   In this  context, we read the  district court to be
            saying not  that  the  EXIS  evidence was  necessary  to  its
                                                       _________
            decision, but  only that  it provided additional  support for
            it.

                                         -41-
                                          41

            presence  of  several different  strong sources  of testimony

            relating Trenkler's admissions, convinces us that no rational

            jury could have entertained  a reasonable doubt of Trenkler's

            guilt even in the absence of the EXIS-derived evidence.25

            C.  Shay Jr.'s Out-of-Court Statements
            ______________________________________

                      Trenkler  additionally  asserts  that the  district

            court erred by admitting  testimony relating ten out-of-court

            statements purportedly  uttered by Shay Jr.   The statements,

            in general, tended to  implicate Shay Jr. in the  bombing and

            to suggest that Shay  Jr. had not acted alone.   The district

            court admitted the  statements either as  nonhearsay evidence

            of Shay  Jr.'s state of  mind, see  Fed. R.  Evid. 801(c);  2
                                           ___

            McCormack   269 at 208, or as falling within the declaration-
            _________

            against-penal-interest exception  to  the hearsay  rule,  see
                                                                      ___

            Fed. R. Evid. 804(b)(3).  Trenkler argues that  the admission

            of  these   statements   violated  his   rights   under   the

            Confrontation Clause.26  We do not agree.

                                
            ____________________

            25.  We agree with our dissenting brother that we may find an
            error harmless beyond a reasonable  doubt only when the other
            evidence in the case, "standing alone, provides `overwhelming
            evidence'  of  the  defendant's  guilt."    See  infra at  53
                                                        ___  _____
            (quoting Clark v. Morgan,  942 F.2d 24, 27 (1st  Cir. 1991)).
                     _____    ______
            In  contrast with  our colleague,  however, we  believe that,
            when the  evidence of Trenkler's participation  in the Quincy
            bombing, which we do not believe was rendered inadmissible by
            the admission  of the EXIS-derived evidence, is  added to the
            "substantial"  other   evidence  of  Trenkler's   guilt,  the
            resulting sum is clearly "overwhelming."

            26.  We  do  not  understand  Trenkler  to  assert  that  the
            district  court committed  error under  the Federal  Rules of
            Evidence in  admitting the statements.   Though Trenkler does

                                         -42-
                                          42

                      In  asserting  a  Confrontation  Clause  violation,

            Trenkler  relies primarily  on Bruton  v. United  States, 391
                                           ______     ______________

            U.S. 123 (1968),  in which the Supreme Court held  that, in a

            joint trial,  an instruction  to  the jury  to disregard  the

            confession  of one non-testifying  defendant was insufficient

            to prevent the confession from unfairly prejudicing the other

            defendant.   Critical to the  Bruton Court's decision was the
                                          ______

            trial  court's  undisputed  ruling  that the  confession  was

            inadmissible  against the non-confessing  defendant.   Id. at
                                                                   ___

            128  n.3.   Bruton has  no application  in the  present case,
                        ______

            however, because the challenged statements here were directly

            admissible against Trenkler and,  consequently, did not  pose

            the Bruton risk of  spill-over prejudice.  In this  case, the
                ______

            district court  admitted the  statements against  Trenkler to

            establish the existence of the conspiracy.  

                      The Confrontation Clause does not proscribe the use

            of  all out-of-court statements.   See  Idaho v.  Wright, 497
                                               ___  _____     ______

            U.S. 805, 813 (1990).   In general, nonhearsay statements  or

            statements  not  offered to  prove  the truth  of  the matter

            asserted   do  not   raise  Confrontation   Clause  concerns.

            Tennessee v. Street, 471 U.S.  409, 414 (1985); United States
            _________    ______                             _____________

            v. Levine, 5 F.3d  1100, 1107 (7th Cir. 1993),  cert. denied,
               ______                                       _____ ______

                                
            ____________________

            state at  one point  that the declarations  "were erroneously
            admitted  .  .  .  as  statements  against  Shay Jr.'s  penal
            interest or of Shay Jr.'s state of mind," he does not explain
            this assertion of error except on constitutional grounds. 

                                         -43-
                                          43

            114 S. Ct. 1224  (1994).  Moreover, the  Confrontation Clause

            does not  necessarily prohibit the use  of hearsay statements

            where  the  trial  court  has admitted  them  pursuant  to  a

            "firmly-rooted"  exception  to   the  hearsay  rule   or  has

            otherwise found  the  statements to  possess  "particularized

            guarantees of trustworthiness."  See Wright, 497 U.S.  at 816
                                             ___ ______

            (citing Ohio v. Roberts, 448 U.S. 56, 66 (1980)).
                    ____    _______

                      To the extent that  the district court admitted the

            statements as nonhearsay  evidence, Trenkler's  Confrontation

            Clause challenge lacks merit.   See Street, 471 U.S.  at 414.
                                            ___ ______

            As for the  rest, we have strongly suggested  previously that

            the exception  for declarations  against penal interest  is a

            "firmly rooted" exception  to the hearsay  rule.  See  United
                                                              ___  ______

            States v. Seeley, 892  F.2d 1, 2 (1st Cir.  1989) ("exception
            ______    ______

            for  declarations against  penal  interest would  seem to  be

            `firmly   rooted'").    Trenkler   does  not  challenge  this

            assumption,  nor  does  he  explain  why  the  statements  in

            question lack "particularized guarantees of trustworthiness."

            Accordingly,  we are  not persuaded  that the  district court

            violated Trenkler's confrontation rights by admitting them.

                                         III.
                                         III.
                                         ____

                                      Conclusion
                                      Conclusion
                                      __________

                      For the  foregoing  reasons, we  affirm  Trenkler's

            conviction.

                                         -44-
                                          44

                                          Dissent follows.
                                          Dissent follows.

                                         -45-
                                          45

                      TORRUELLA, Chief Judge, (Dissenting).   In my view,
                      TORRUELLA, Chief Judge, (Dissenting).
                                 ___________

            the erroneous admission in this case of evidence derived from

            the  EXIS computer  database  violated the  defendant's Sixth

            Amendment right to confront  witnesses against him.  Contrary

            to my brethren, I do not believe that this error was harmless

            beyond a reasonable doubt.  I therefore dissent.

                                          I.
                                          I.
                                          __

                      Trenkler   admitted  to  building   a  device  that

            exploded  in  Quincy  in  1986.    The  government's  central

            strategy at trial27 was  to prove that the Quincy  device was

            so similar to the Roslindale bomb  that they had to have been

            built by  the same person.   Stephen Scheid,  an Intelligence

            Research Specialist  with the Bureau of  Alcohol, Tobacco and

            Firearms  ("ATF"), testified  that  he  conducted a  computer

            query  on   the  ATF's  EXIS  database28   to  identify  bomb

            incidents  which  shared  certain  characteristics  with  the

            Roslindale incident.  Based on this analysis, Scheid told the

            jury that,  out of the 14,252 bombings and attempted bombings

            reported  in  EXIS,  only   the  Roslindale  and  the  Quincy

            incidents shared all the queried characteristics.

                      For a jury  reviewing otherwise weak circumstantial

            evidence of  defendant's guilt (see infra),  this is powerful
                                            ___ _____

                                
            ____________________

            27.  In  support of its motion in limine to admit evidence of
            the 1986 incident, the  government described this evidence as
            "the centerpiece of the Government's case in chief."

            28.  For a description of the EXIS database, see supra p. 8.
                                                             _____

                                         -46-
                                          46

            stuff  --  tangible,  "scientific"  evidence which  seems  to

            conclusively  establish that  the  same person  who made  the

            Quincy  device in  1986  made the  Roslindale  bomb in  1991.

            Unfortunately, as  the majority  concedes,  the reports  from

            which the EXIS information is derived are utterly unreliable,

            thus  rendering its  conclusion equally  unreliable, and,  as

            will  be shown,  completely  misleading.   For three  related

            reasons,  I  disagree  with  the majority's  conclusion  that

            admission of the EXIS-derived  evidence  was "harmless beyond

            a  reasonable  doubt."    First,  the  EXIS-derived  evidence

            plainly influenced the district court's decision to allow the

            government's motion to admit evidence of the Quincy incident,

            under Fed. R. Evid. 404(b), to show that the same person must

            have  built the  Roslindale bomb.   Second,  the EXIS-derived

            evidence  was very powerful and very  misleading.  Third, the
                          ____              ____

            other evidence against Trenkler was not "overwhelming," as is

            required under our precedent.

                                         II.
                                         II.
                                         ___

                      The  majority  assumes,   without  deciding,   that

            Trenkler's  Sixth  Amendment  right  to   confront  witnesses

            against him was violated  by introduction of the EXIS-derived

            evidence.     Supra  n.22.    As   the  majority  recognizes,
                          _____

            constitutional cases  are  governed by  a stringent  harmless

            error analysis -- a conviction cannot stand unless the effect

            of  the evidence  is  "harmless beyond  a reasonable  doubt."
                                   ____________________________________

                                         -47-
                                          47

            Chapman  v.  California, 386  U.S.  18,  24 (1966)  (emphasis
            _______      __________

            added); United  States v.  De Jes s-R os, 990  F.2d 672,  678
                    ______________     _____________

            (1st  Cir.  1993).29   To  comprehend  why admission  of  the

            EXIS-derived  evidence was  not harmless beyond  a reasonable

            doubt,  one must  understand  the nature  and  extent of  the

            constitutional  violation.     Because  the  majority  barely

            acknowledges, much less  discusses, the constitutional  right

            at stake in this case,  its result appears both  analytically

            sound and benign.  It is  neither.  I will therefore begin by

            explaining  why,   and  to  what   extent,  Trenkler's  Sixth

            Amendment   right  to  confront  witnesses  against  him  was

            violated.  I will then endeavor to show why this error cannot

            be considered harmless.

                                         III.
                                         III.
                                         ____

                      The  Confrontation Clause  of  the Sixth  Amendment

            provides  that, "[i]n all  criminal prosecutions, the accused

            shall  enjoy  the right  .  .  . to  be  confronted  with the

            witnesses against him."  The Supreme Court has explained that

            "[t]he  central concern  of  the Confrontation  Clause is  to

            ensure  the reliability  of the  evidence against  a criminal

            defendant by subjecting it to rigorous testing in the context

                                
            ____________________

            29.  Under  the standard  for analyzing  harmless error  in a
            non-constitutional case, the court  will uphold a  conviction
            provided  it  can  be  said  "that   the  judgement  was  not
            substantially swayed by the error."  United States v. Flores,
                                                 _____________    ______
            968 F.2d 1366, 1372 n.7 (1st Cir. 1992) (quoting Kotteakos v.
                                                             _________
            United States, 328 U.S. 750, 765 (1946)). 
            _____________

                                         -48-
                                          48

            of  an  adversary  proceeding  before  the  trier  of  fact."

            Maryland v. Craig, 497 U.S. 836, 845 (1990); United States v.
            ________    _____                            _____________

            Zannino, 895 F.2d  1, 5 (1st Cir. 1990) ("the  mission of the
            _______

            Confrontation Clause  is to  advance a practical  concern for

            the  accuracy of  the truth-determining  process  in criminal

            trials  by assuring that the trier of fact has a satisfactory

            basis  for  evaluating the  truth  of  the prior  statement")

            (quoting Dutton v. Evans, 400  U.S. 74, 89 (1970)  (plurality
                     ______    _____

            opinion)).

                      Hearsay  evidence  from an  unavailable declarant30

            may only be admitted  against a defendant in a  criminal case

            if the government can demonstrate that the proffered evidence

            "bears adequate  indicia of  reliability."  Ohio  v. Roberts,
                                                        ____     _______

            448   U.S.   56,   66  (1980)   (internal   quotation   marks

            omitted).31    The  government  may satisfy  this  burden  by

                                
            ____________________

            30.  For practical  purposes, the authors of  the over 14,000
            underlying  EXIS reports  were  effectively "unavailable"  in
            this case.   See United  States v. Inadi,  475 U.S. 387,  394
                         ___ ______________    _____
            (1986) (absolute unavailability not constitutionally required
            in  all cases); Manocchio v. Moran, 919 F.2d 770, 774-76 (1st
                            _________    _____
            Cir. 1990) (same).  

            31.  The  majority  properly   holds  that  the  EXIS-derived
            statement  --  that out  of  more  than  14,000 bombings  and
            attempted bombings  in the EXIS database  only the Roslindale
            and   Quincy   incidents    shared   the   specific   queried
            characteristics -- is inadmissible  totem pole hearsay.  That
            is,  it was based on  a host of  out-of-court statements (the
            14,252  underlying  reports  submitted  by  unknown  authors)
            offered  in  court for  the  truth  of the  matters  asserted
            therein (the characteristics of those bombings).  See Fed. R.
                                                              ___
            Evid.  801.   Because  we know  neither  who submitted  those
            underlying reports,  nor under what  conditions, the majority
            properly  holds that the statements do not satisfy any of the

                                         -49-
                                          49

            establishing either that the  evidence "falls within a firmly

            rooted  hearsay exception"  or by  showing that  the evidence

            possesses  "particularized  guarantees of   trustworthiness."

            Id.; accord  Idaho v.  Wright,  497 U.S.  805, 816-17  (1990)
            __   ______  _____     ______

            (collecting cases); Manocchio, 919 F.2d at 773.  The majority
                                _________

            properly  holds  that  the  EXIS-derived  evidence  satisfies

            neither of these criteria, but neglects to fully explain why.

                      The     critical     inquiry    for     determining

            "particularized  guarantees  of  trustworthiness" is  whether

            "the test of cross-examination would be of marginal utility."

            Wright,  110 S.  Ct. at  3149-50.32   The government  in this
            ______

            case,  through  Scheid,  was   permitted  to  introduce   the

            statement that,  out of 14,252 bombing  and attempted bombing

            incidents  in  the EXIS  database,  only  the Roslindale  and

            Quincy  incidents  share the  queried  characteristics.   The

            individuals who reported those bomb incidents  were witnesses

            against Trenkler,  each of them testifying,  in effect: "This

            bomb incident  had the  following characteristics  .  . .  ."

            Despite the importance of their "testimony," neither Trenkler

            nor the jury  ever saw  any of these  witnesses.   Trenkler's

            attorney  was unable  to cross-examine  these witnesses  with

                                
            ____________________

            hearsay exceptions listed in Fed. R. Evid. 803(1)-(24).  

            32.  The  residual  hearsay  exception contained  in  Fed. R.
            Evid. 803(24), under which the EXIS evidence was admitted, is
            not a  "firmly  rooted  hearsay  exception."   See  Idaho  v.
                                                           ___  _____
            Wright,  497  U.S.  805,  817 (1990);  Government  of  Virgin
            ______                                 ______________________
            Islands v. Joseph, 964 F.2d 1380, 1387 (3d Cir. 1992). 
            _______    ______

                                         -50-
                                          50

            respect to  their credibility and reliability.   Because they

            were  not subject  to cross-examination,  neither we  nor the

            jury  will  ever  know,  for  example,  the  answers  to  the

            following questions.  Were the authors of these reports  bomb

            experts?   Were they even  police officers?   Did they follow

            certain procedures  in compiling  evidence?  In  filing their

            reports?  What criteria did they use for determining that the

            device in question was  a quote "bomb"?   Did they even  have

            first hand knowledge of  the devices, or was the  information

            provided to them second-hand from lay  witnesses?  Scheid did

            not  know the  answers to  these questions,  nor did  he have

            first hand  knowledge of  the incidents themselves,  supra p.
                                                                 _____

            34,  thus making  it  impossible for  Trenkler's attorney  to

            effectively cross-examine  him.   Moreover,  Scheid  admitted

            that  the bomb reports need  not be signed,  and that nothing
                                   ___________________

            required the author  of a submitted  report to have  personal

            knowledge of its contents.33

                      The majority  also alludes  to  a potentially  more

            pernicious problem concerning the EXIS-derived evidence.  The

            majority  notes that  the database  entry for  the Roslindale

            incident   lists  approximately   twenty-two  characteristics

                                
            ____________________

            33.  Even  the majority  questions the  validity of  the EXIS
            conclusion that only the  Roslindale and Quincy devices share
            the  same  characteristics.    As the  majority  points  out,
            because we  know absolutely nothing about  how the underlying
            EXIS reports were generated, there is no way to know what the
            absence of an item at a bomb site means.  Both Scheid and the
            government's explosives expert admitted as much.  Supra n.21.
                                                              _____

                                         -51-
                                          51

            describing  that  incident, but  Scheid,  inexplicably, chose

            only  to query ten  of those characteristics.34   Supra n.21.
                                                              _____

            The  majority notes  that there  is nothing  to suggest  that

            these  ten  characteristics are  more  important  to a  bomb-

            signature analysis than any  of the other characteristics not

            chosen.  Scheid offers  no reason why he chose to  query only

            certain generic characteristics instead  of the more specific

            characteristics of  the Roslindale bomb, which  would be more

            evincing of  a "signature."   For example, the  Quincy device

            would not have been a match if Scheid had queried  any of the

            following  characteristics of the  Roslindale bombing: Futaba

            antenna, Rockstar detonator, use of dynamite, nails, glue, 6-

            volt battery,  slide switch,  paint, magazine page,  or black

            electrical  tape.    The   majority  leaves  the  implication

            unspoken.     I  will  not  be  so  discreet.    The  obvious

            implication   is   that    Scheid   chose   the    particular

            characteristics in an attempt to find a match with the Quincy

            device.   This  implication  is enforced  by  the fact  that,

                                
            ____________________

            34.  The  queried   characteristics  were  1)   bombings  and
            attempted bombings; 2) involving cars or trucks; 3) with bomb
            placed  under the car or  truck; 4) using remote-control; and
            5) magnets.  EXIS listed seven incidents which included these
            characteristics.   Scheid testified that he  then performed a
            manual   query   of   the   seven   incidents   using   other
            characteristics of  the Roslindale  bombing.  He  checked the
            other  incidents to  see if  they involved  1) duct  tape; 2)
            soldering;  3) AA batteries; 4) a toggle switch; and 5) round
                                                                    _____
            magnets.   Scheid  did  not  check all  14,252  bombings  and
            attempted bombings for these latter characteristics, only the
            seven.  

                                         -52-
                                          52

            according to Scheid's own  testimony, the Quincy incident was

            not  entered into  the  database until  after the  Roslindale
                                                    _____

            incident.   That  is,  government agents  brought the  Quincy

            bombing  to  Scheid's  attention   when  they  asked  him  to

            investigate the Roslindale bombing.  

                      The majority  thinks these concerns go  more to the

            weight  of the  evidence than  to its  admissibility;  to the

            contrary,  they go directly  to the  question of  whether the

            evidence  has  particularized  guarantees of  trustworthiness

            under  the Confrontation  Clause.   They demonstrate  that it

            does not.  Because  the reports upon which the  EXIS evidence

            is  based are  inherently  and utterly  unreliable, the  EXIS

            evidence  itself is  inherently and  utterly unreliable,  and

            Trenkler's Sixth  Amendment right  to confront  the witnesses

            against him was violated.  See  Wright, 497 U.S. at 805.  The
                                       ___  ______

            question then becomes whether  this error was harmless beyond

            a reasonable doubt.35

                                
            ____________________

            35.  This Circuit has demonstrated  that it is not shy  about
            applying  the  harmless  error  rule to  sustain  a  criminal
            conviction, but rather, shows  a persistent inclination to so
            rule.   See, e.g., United  States v. Romero-Carri n,  1995 WL
                    ___  ____  ______________    ______________
            258843 (1st Cir.);  United States v. Cotal-Crespo, 47  F.3d 1
                                _____________    ____________
            (1st  Cir. 1995); United States  v. Smith, 46  F.3d 1223 (1st
                              _____________     _____
            Cir.  1995); United States v.  Lewis, 40 F.3d  1325 (1st Cir.
                         _____________     _____
            1994);  United States v.  Tuesta-Toro, 29 F.3d  771 (1st Cir.
                    _____________     ___________
            1994); Singleton  v. United  States,  26 F.3d  233 (1st  Cir.
                   _________     ______________
            1994);  United States v. Isaacs, 14 F.3d 106 (1st Cir. 1994);
                    _____________    ______
            United  States v. Welch; 15 F.3d 1202 (1st Cir. 1993); United
            ______________    _____                                ______
            States v. Sep lveda,  15 F.3d  1161 (1st  Cir. 1993);  United
            ______    _________                                    ______
            States v.  Innamorati, 996 F.2d  456 (1st Cir.  1993); United
            ______     __________                                  ______
            States  v. Williams,  985 F.2d  634  (1st Cir.  1993); United
            ______     ________                                    ______
            States  v.  Spinosa, 982  F.2d  620 (1st  Cir.  1992); United
            ______      _______                                    ______

                                         -53-
                                          53

                                         IV.
                                         IV.
                                         ___

                      Under  the  harmless  beyond  a   reasonable  doubt

            standard, we  must vacate  the conviction  if there  is "some

            reasonable possibility that error of constitutional dimension
            ______________________

            influenced the jury in reaching [its] verdict." United States
            __________                                      _____________

            v. Majaj, 947  F.2d 520,  526 n.8 (1st  Cir. 1991)  (emphasis
               _____

            added) (quoting United States v. Argentine, 814 F.2d 783, 789
                            _____________    _________

            (1st Cir. 1987)).  See also United States v. Flores, 968 F.2d
                               ________ _____________    ______

            1366, 1372 (1st  Cir. 1992).   Under this  standard, we  will

            only  find  harmless  error  when  the  untainted   evidence,

            standing  alone,  provides  "overwhelming  evidence"  of  the

            defendant's guilt.  Clark v. Moran, 942 F.2d 24, 27 (1st Cir.
                                _____    _____

            1991).   In  conducting this inquiry,  we "must  consider the

            evidence  as a  whole,  weighing the  effect  of the  tainted

            evidence  against  the  effect  of that  evidence  which  was

            properly admitted."   Id. (citing Lacy  v. Gardino, 791  F.2d
                                  __          ____     _______

            980, 986  (1st  Cir.), cert.  denied, 479  U.S. 888  (1986)).
                                   _____________

            Thus, the  relative strength of the tainted evidence -- i.e.,

                                
            ____________________

            States v.  Figueroa, 976 F.2d  1446 (1st  Cir. 1992);  United
            ______     ________                                    ______
            States v. Tejeda, 974 F.2d 210 (1st Cir. 1992); United States
            ______    ______                                _____________
            v.  Parent, 954  F.2d 23  (1st Cir.  1992); United  States v.
                ______                                  ______________
            Karas, 950 F.2d 31 (1st Cir. 1991); United States v. Minnick,
            _____                               _____________    _______
            949 F.2d 8 (1st Cir. 1991); United States v. Maraj, 947  F.2d
                                        _____________    _____
            520 (1st  Cir. 1991); Clark v.  Moran, 942 F.2d  24 (1st Cir.
                                  _____     _____
            1991); United States v. McMahon, 938 F.2d 1501 (1991); United
                   _____________    _______                        ______
            States v. Brown, 938 F.2d 1482 (1st Cir. 1991); United States
            ______    _____                                 _____________
            v.  Ellis, 935  F.2d 385  (1st cir.  1991); United  States v.
                _____                                   ______________
            Sutherland, 929  F.2d 765 (1st  Cir. 1991); United  States v.
            __________                                  ______________
            Wood, 924 F.2d 399  (1st Cir. 1991); United States  v. Paiva,
            ____                                 _____________     _____
            892 F.2d 148 (1st Cir. 1989). 

                                         -54-
                                          54

            its potential effect on  the jury -- is a  highly significant

            consideration.

                      As I  see it, there  are three related  reasons why

            admission of the EXIS  evidence cannot be considered harmless

            beyond a reasonable doubt.  First, it is clear to me that the

            district court  relied on the  improper EXIS evidence  in its

            decision  to allow the government  to present evidence of the

            Quincy incident  to  the jury  to prove  identity under  Rule

            404(b).

                      At the hearing  on its  motion in  limine to  admit

            evidence of the  Quincy incident under Fed. R.  Evid. 404(b),

            the government presented the  testimony of Scheid,  regarding

            the  EXIS  computer  analysis,   and  the  testimony  of  the

            government's bomb expert, Waskom,  who testified that, in his

            opinion, the  Quincy and  Roslindale devices were  so similar

            that they must have been built by the same person.   In turn,

            Trenkler presented expert testimony that the devices were too

            different for anyone  to be  able to determine  if they  were

            built by the same  person.  After hearing this  evidence, the

            district court concluded that  "the similarities [between the

            two incidents] are sufficient to admit the evidence under the

            rules established . . . by the First Circuit."

                      The majority states that,  based upon its review of

            the record, it is convinced that the EXIS-based evidence "was

            not a  critical factor  in the  district court's decision  to

                                         -55-
                                          55

            admit the Quincy bomb evidence for purposes of identity.  The

            EXIS-derived  evidence  was merely  cumulative, corroborating

            the testimony of the  government's explosives expert."  Supra
                                                                    _____

            pp.  39-40.   Yet the record  demonstrates that  the district

            court  judge  thought otherwise  when  she  decided to  admit

            evidence of the 1986 Quincy incident.  In her oral opinion on

            the government's  motion, the  district court judge  began by

            summarizing the testimony of Waskom, and then stated: "Adding
                                                                   ______

            to  this evidence,  the  statistical evidence  from the  EXIS
            _________________

            system, I am persuaded that the  two devices are sufficiently

            similar  to prove that the  same person built  them, and thus

            relevant to the issues in this case."  (emphasis added).  The

            district  court  judge did  not  say that  the  EXIS evidence

            "corroborated" Waskom's testimony.  She stated that, when she

            adds  the EXIS  evidence to  Waskom's testimony,  she becomes
            ____

            convinced that the  two devices are sufficiently similar.  It

            is plain that  the district  court judge relied  on the  EXIS

            evidence to  form the  critical final  link  between the  two

            devices.  Indeed, in arguing its motion, the government chose

            to  first present the EXIS  evidence and then  to present the

            Waskom testimony,  suggesting that it intended  the latter to

            corroborate  the  former.    The district  court's  erroneous

            determination that  the EXIS evidence was  admissible led not

            only to  the jury hearing that evidence, but also to the jury

            hearing Waskom's testimony with respect to the two incidents.

                                         -56-
                                          56

            I cannot  agree, therefore,  that admission of  this evidence

            was harmless beyond a reasonable doubt.

                      The  second  reason  that  admission  of  the  EXIS

            evidence cannot  be considered harmless is that  this type of

            "scientific" evidence  is too  misleading, too powerful,  and

            has  too  great  a potential  impact  on  lay  jurors, to  be

            disregarded as harmless.

                      The  EXIS-derived  evidence was,  in the  best case

            scenario, unintentionally misleading, and, in the  worst case

            scenario,  deliberately skewed.    Scheid testified  that, in

            entering information about the  Quincy incident into the EXIS

            database, he relied solely on a laboratory report prepared in

            1986 by  investigators from  the Massachusetts  Department of

            Public  Safety.  This report  does not state  that the Quincy

            device was  attached to the  underside of the  Capeway truck.

            Rather,  it  refers  only   to  an  "[e]xplosion  on  truck."

            Somebody must have given Scheid further information about the

            Quincy  explosion because  he  entered "under  vehicle" as  a

            characteristic  of  the  Quincy   incident.    The   majority

            acknowledges these facts but, inexplicably, makes no comment.

            See  supra n.8.  These facts are important for three reasons.
            ___  _____

            First,  they  illustrate the  fallibility  of  the underlying

            reports.   How many of  the other 14,232  reports had similar

            defects?   Second, they illustrate  how easily  one wrong  or

            incomplete  entry can affect a  query result.   If Scheid had

                                         -57-
                                          57

            actually followed  the report, the Quincy  incident would not

            have  matched the Roslindale  bombing because  Scheid's query

            entry  was  for  a  bomb "under  vehicle."36  Finally,  these

            facts  indicate  that  the  EXIS  test  was  skewed  (whether

            intentionally or unintentionally) to find a match between the

            Quincy and Roslindale incidents.37

                      The  EXIS-derived  evidence   is  also   misleading

            because it focuses the jury's attention on  the trees instead

            of the forest. By  focusing on similar minor aspects  between

            the  two devices -- e.g., duct tape, magnets and soldering --

            the  majority  completely brushes  aside  the  fact that  the

            central and most  important ingredient in the  two devices is

            fundamentally different.   The central ingredient  in a bomb,

            one would think, is  the explosive content (in much  the same

            way that the central ingredient in a high-performance  car is

            the engine).  The Roslindale bomb used two to three sticks of

            dynamite  -- a very  powerful explosive.   The  Quincy device
            ________

            used an M-21 Hoffman  artillery simulator, which is a  device

                                
            ____________________

            36.  The majority acknowledges that "[t]he statement that out
            of more  than 14,000 bombing and  attempted bombing incidents
            in the EXIS database only the Roslindale and Quincy incidents
            share  the eight  specific queried  characteristics (bombings
            and attempted bombings, attached  under car or truck, remote-
            control,  round magnets,  duct  tape,  solder, AA  batteries,
            toggle switches) is a  fairly powerful statement, but perhaps
                                _________________________________________
            a somewhat misleading one."  Supra n.21 (emphasis added).
            _________________________    _____

            37.  As discussed previously, there is other  evidence (i.e.,
            the suspect nature of Scheid's query choices) which  tends to
            show  that the  EXIS query  may have been  skewed to  reach a
            predictable result.  See supra pp. 50-51. 
                                 ___ _____

                                         -58-
                                          58

            used  by the  military to  simulate, in  a safe  fashion, the
                                   _________________________________

            flash and noise of artillery.  The simulator is, in effect, a

            firecracker-like device; it has no where near the strength of

            dynamite.   In stark contrast to dynamite, a simulator is not

            designed to cause physical or property damage.  Indeed, while

            the Roslindale  device created  an explosion large  enough to

            kill, the Quincy device caused no visible damage to the truck

            it  was placed  under.   Equating  the  two devices  is  like

            equating a BB gun with a high caliber rifle.38

                      The misleading nature of the EXIS-derived statement

            is compounded  by the nature  of its  source, and the  way in

            which it  was presented  to the  jury.  Not  only is  it rank

            hearsay evidence, it is hearsay evidence wrapped in a  shroud

            of "scientific" authenticity.  This  is not a paid government

            expert testifying that, in his opinion, the two  devices were
                                    ______________

            built by the same  person; this is a computer  declaring that
                                                 ________

            the two devices  were built  by the same  person.   Computers

            deal in facts,39  not opinions.   Computers are  not paid  by

                                
            ____________________

            38.  Federal authorities apparently  did not deem the  Quincy
            incident serious enough to  warrant bringing charges  against
            Trenkler  pursuant   to   18  U.S.C.      844(i)   (malicious
            destruction of property by means of an explosive), one of the
            statutes  at issue in this case.  State charges stemming from
            the Quincy incident were dismissed.

            39.  Of course,  the facts generated by the computer are only
            as accurate  and reliable  as the  facts fed  into it  by its
            operator.  As the majority recognizes, in this case the facts
            fed  into  the  computer   were,  unbeknownst  to  the  jury,
            manifestly unreliable.   Thus, its conclusion  based on those
            facts is similarly unreliable.

                                         -59-
                                          59

            one side to testify.  Computers do not have  prejudices.  And

            computers  are not subject  to cross-examination.   Moreover,

            the  chart of the EXIS  queries performed by  Scheid, and the

            printouts of  the results  of those queries,  were introduced

            into  evidence  and  presented   as  exhibits  to  the  jury.

            Consequently, the jury had this misleading, physical evidence

            with them in the  jury room during deliberations.40   Does it

            not  stand to reason that  the lay juror  will accord greater

            weight to a computer's written findings than to the testimony

            of a government expert witness?   The common-sense answer is,

            of course.41

                                
            ____________________

            40.  Common sense  tells us that  lay jurors often  will lend
            more weight to tangible evidence than to oral testimony.  See
                                                                      ___
            generally  22  C.  Wright  &  Graham,  Federal  Practice  and
            _________                              ______________________
            Procedure,    5173 (1978)  ("It is  often  asserted that  the
            _________
            psychological  impact  of  the  concrete has  a  capacity  to
            suggest  matters  not  proved,  to  lead  the  jury  to  draw
            unconscious inferences that would not be drawn if  the object
            was  the subject of  testimony rather than  being produced in
            court.") (internal  citations omitted).   See also  People v.
                                                      ___ ____  ______
            Moore, 525 N.E.2d 460, 463 (N.Y. 1988) (Kaye, J., dissenting)
            _____
            ("No  point in  a  trial  can  be  more  critical  than  jury
            deliberations.   Materials taken into the jury  room at those
            crucial moments may well influence the verdict.").

            41.  As one commentator has noted:

                           Scientific  evidence  impresses
                           lay  jurors.    They   tend  to
                           assume it is more  accurate and
                           objective  than lay  testimony.
                           A    juror   who    thinks   of
                           scientific  evidence visualizes
                           instruments      capable     of
                           amazingly  precise measurement,
                           of   findings  arrived   at  by
                           dispassionate scientific tests.
                           In  short, in  the mind  of the

                                         -60-
                                          60

                      The majority decision in  this case not only defies

            common sense,  it is also contrary  to our precedent.   In De
                                                                       __

            Jes s-R os, 990  F.2d 672, we  held that the  defendant's due
            __________

            process rights were violated when the district court admitted

            certain    identification    testimony    by    a    witness.

            Significantly, we  concluded that the error  was not harmless

            beyond  a  reasonable  doubt,  even  though  another  witness

            testified at trial that he also had identified the defendant.

            Rather than concluding, as  the majority does here, that  the

            one   erroneously   admitted   identification   was   "merely

            cumulative" of the other, the court reasoned:

                      [T]here is  no way for us  to discern the
                      role that  Rivera's identification played
                      in  the jury's  deliberations.    We  are
                      concerned  that the  jury  may have  been
                                                 ______________
                      persuaded to  convict  by the  very  fact
                      _________________________________________
                      that   there   were  two   witnesses  who
                      ____________________________________
                      identified [the  defendant].  It  is also
                      possible that the jury relied solely upon
                      the testimony of  Rivera in reaching  its

                                
            ____________________

                           typical lay juror, a scientific
                           witness has a  special aura  of
                           credibility.

            Imwinkelried, Evidence Law and  Tactics for the Proponents of
                          _______________________________________________
            Scientific Evidence, In Scientific and Expert Evidence 33, 37
            ______________________________________________________
            (E.  Imwinkelried  ed.  1981).     See  also  Giannelli,  The
                                               _________              ___
            Admissibility of  Novel Scientific  evidence: Frye  v. United
            _____________________________________________
            States, a  Half-Century Later, 80  Colum. L. Rev.  1197, 1237
                    _____________________
            (1980)  ("The  major danger  of  scientific  evidence is  its
            potential  to  mislead  the   jury;  an  aura  of  scientific
            infallibility may  shroud the evidence and thus lead the jury
            to accept  it without  critical scrutiny.");  22 C.  Wright &
            Graham, supra note 41,   5217 ("Scientific . . . evidence has
                    _____
            great  potential for misleading the jury.   The low probative
            worth can often be concealed in the jargon of some expert . .
            .").

                                         -61-
                                          61

                      conclusion.    Thus,  we find  reasonable
                      doubt exists as to whether the jury would
                      have  convicted   [the  defendant]  based
                      solely   upon   Mejias's   identification
                      testimony.

            Id. at 678  (emphasis added).   Is it  not equally  plausible
            __

            that  the jury  in  this case  "may  have been  persuaded  to

            convict"  by the very fact that two "witnesses" -- Waskom and

            the  EXIS-derived evidence  --  identified the builder of the

            Quincy  device as the builder of the  Roslindale bomb?  Is it

            not also equally plausible  that the jury relied solely  upon
                                                             ______

            the  EXIS-derived  evidence   in  reaching  its   conclusion?

            Because the EXIS-derived statement  came from a computer, and

            was presented in tangible, exhibit  form, it is more powerful

            and  seemingly credible  evidence  to  a  lay jury  than  the

            testimony of a human being.  The jury may well have relied on

            the  EXIS-derived  evidence  to  break the  tie  between  the

            competing experts.   This  is particularly  so since, as  the

            trial   judge   noted,   defendant's   expert   witness   had

            "considerably  more  experience in  making  .  . .  signature

            comparisons."   Since  the EXIS-derived  evidence  could well

            have   been  "the  clincher"  for  the  jury,  it  cannot  be

            considered harmless  beyond a reasonable doubt.   See Coppola
                                                              ___ _______

            v. Powell, 878 F.2d 1562 (1st Cir. 1989).
               ______

                      The  third  reason  that  admission  of   the  EXIS

            evidence is  not harmless beyond  a reasonable doubt  is that

            the other evidence  against Trenkler was  not "overwhelming."

                                         -62-
                                          62

            See Clark,  942  F.2d  at  27.   The  majority  points  to  a
            ___ _____

            conglomeration   of  other  testimony   in  support   of  its

            conclusion   that  there   was   "substantial  evidence"   of

            Trenkler's guilt,  independent of  the Quincy incident.   The

            test,  of  course,  is  not  whether  there  is  "substantial

            evidence"   of  Trenkler's   guilt  but   whether  there   is

            "overwhelming  evidence"  of  Trenkler's   guilt.    The  two
             ____________

            standards are qualitatively and quantitatively different.  In

            any case, I will  begin by addressing Trenkler's "statements"

            to government agents.

                      ATF  Agent  D'Ambrosio  testified  that   he  asked

            Trenkler  to  draw  a  sketch of  the  Quincy  device,  which

            Trenkler  did.    D'Ambrosio  then  told  Trenkler  that  the

            Roslindale bomb  also used  remote control, but  that, rather

            than a firecracker type device, it used dynamite.  D'Ambrosio

            asked  Trenkler  how, in  light  of these  facts,  the wiring

            diagram  he had just drawn  for the Quincy  device would have

            been  different for the Roslindale bomb. D'Ambrosio testified

            that Trenkler then drew  a diagram which showed  two blasting

            caps  inserted into  two sticks  of  dynamite.   The majority

            considers  this  significant  evidence  of  Trenkler's  guilt

            because the fact that the Roslindale bomb used blasting  caps

            had not been publicly disclosed.  The majority fails to note,

            however, that D'Ambrosio actually testified that at least two
                                                             ________

            blasting caps  were used  in the  Roslindale bombing.   Thus,

                                         -63-
                                          63

            Trenkler's drawing of only two blasting caps was not an exact

            match.  Moreover,  the jury heard evidence that  Trenkler had

            extensive knowledge of both electronics and explosives, so it

            is  not necessarily  significant  that Trenkler  was able  to

            reconstruct an  aspect of  the Roslindale bomb,  particularly

            considering the  information concerning the bomb  provided to

            Trenkler  by D'Ambrosio.    Trenkler  merely identified  that

            blasting caps  were a likely way in which a bomb of this size

            and  power would  be  constructed.   In  the absence  of  any

            testimony  that the use of blasting caps is unusual or unique

            (a proposition which is highly unlikely), the jury could only

            speculate as to the significance of the drawing.

                      The majority  also finds significance in  ATF Agent

            Leahy's testimony that Trenkler  said to him: "If we  did it,

            then only we know about it . . . how will you ever find out .

            .  . if neither one of us  talk[]?"  The majority paints this

            statement in a confessional light.  This testimony may or may

            not have  been of some  circumstantial relevance to  the jury

            (although  standing  alone,  of   course,  it  would  not  be

            sufficient  to sustain a conviction).  But, upon review, when

            the court  is looking  for "overwhelming evidence  of guilt,"

            one would  think the court would  not have to resort  to this

            sort of  an ambiguous, taunting statement.42   Similarly, the

                                
            ____________________

            42.  In  Coppola,  for  example,  we lent  little  weight  to
                     _______
            defendant's statement to  another inmate -- "What did  I have
            to  lose?"  --  in response  to  a  question  whether he  had

                                         -64-
                                          64

            court notes that  there was evidence  that Trenkler and  Shay

            knew  each other,  and that  Trenkler  had knowledge  of both

            electronics and  explosives.   While the jury  might consider

            this type of circumstantial  evidence relevant, it can hardly

            be  said  that  it   does  much  in  the  way   of  providing

            "overwhelming  evidence" of  defendant's guilt.   Cf.  United
                                                              __   ______

            States  v.  Innamorati, 996  F.2d  456, 476  (1st  Cir. 1993)
            ______      __________

            (holding that the  erroneous admission  of inculpatory  grand

            jury testimony  was harmless  beyond a reasonable  doubt when

            seven people testified at trial that defendant was engaged in
            _____

            marijuana and cocaine dealing, and drugs and money were found

            in defendant's constructive possession).

                      The majority  relies most heavily on  the testimony

            of David  Lindholm, who testified that  Trenkler confessed to

            building the Roslindale bomb.  But Lindholm had  some serious

            credibility problems which make his testimony "shaky," to say

            the  least.  Lindholm  testified that  he met  Trenkler while

            Lindholm was  serving a  97-month sentence for  conspiracy to

            distribute marijuana  and tax evasion.   He further testified

            that he was in the marijuana business from approximately 1969

            through 1988, and that he did not pay any income taxes during

            that  time.  Lindholm also testified that, in order to secure

            bank loans to purchase property during that period, he showed

            several  banks false  income tax  returns.   On the  basis of

                                
            ____________________

            committed the rape.  See 878 F.2d at 1569-70.  
                                 ___

                                         -65-
                                          65

            Lindholm's shady  past alone, the jury  might have completely

            disregarded his testimony.

                      But Lindholm also had some less obvious credibility

            problems.   The circumstances of his  meeting Trenkler strike

            me as a little too coincidental.  On December 17, 1992, after

            a year and a half incarceration in Texas, Lindholm is brought

            back to Boston concerning certain unspecified charges related

            to his conviction.  He is then placed in the orientation unit

            at  the Plymouth  House of  Correction where he  meets Alfred

            Trenkler, who is being held in connection with the Roslindale

            bombing.   The two  subsequently discover that  they have  an

            extraordinary amount  in common.   First, they are  both from

            the town of Milton, Massachusetts.  Second, Trenkler attended

            Thayer Academy and Milton Academy, and Lindholm's father also

            attended Thayer Academy and Milton Academy.  Third, they both

            lived for a time -- overlapping by one year --  on White Lawn

            Avenue  in  Milton.     Based  on  these  commonalities,  and

            Lindholm's   generosity  in  sharing  his  knowledge  of  the

            criminal   justice  system   with  Trenkler,   they   form  a

            friendship.  Trenkler then,  allegedly, confesses to Lindholm

            that he built the bomb.

                      In  my  view,  a  reasonable juror  might  question

            whether Lindholm  was placed in  the orientation unit  by the

            government  for the  purpose of  obtaining a  confession from

            Trenkler.    If so,  that  juror  would  likely  wonder  what

                                         -66-
                                          66

            Lindholm got in return.  Not surprisingly, Lindholm testified

            that he had no agreements with the government and that he did

            not   receive   any   promises   or   inducements   for   his

            testimony.43  He  did testify on  cross-examination, however,

            that he knew, when he provided the information about Trenkler

            to the  government, that the  only way his  97-month sentence

            could  be reduced was if  he supplied new  information to the

            government.44

                      We  do  not  know how  much  weight  the  jury gave

            Lindholm's  testimony, but we do know that, at least on paper

            -- for we  did not observe his demeanor at  trial -- Lindholm

                                
            ____________________

            43.  If  the  government  makes  an  explicit  promise  to  a
            witness,  of course, this will  come out at  trial and likely
            decrease the  witness's credibility in the eyes  of the jury.
            But if the government lawyers explain to the witness why they
            do  not  want to  make  any  explicit promises,  leaving  the
            inference that one good deed begets  another, the witness can
            testify that he  has no agreement.   I note, in this  regard,
            that  this court  has previously  questioned the  validity of
            these "no agreement" statements by criminal defendants.  See,
                                                                     ___
            e.g., Coppola, 878 F.2d at 1569-70.
            ____  _______

            44.  When  asked  on  direct  examination  why  he testified,
            Lindholm stated:

                      Since  I have  been incarcerated,  I have
                      come to realize that the sole function of
                      prison  is not just  punishment.  I think
                      rehabilitation   is   important  for   an
                      individual.   And  I  think, when  I talk
                      about     rehabilitation,      I     mean
                      rehabilitation  of  a person's  values in
                      terms of how they live one's life and the
                      decisions   they    make,   knowing   the
                      decisions   they    make,   knowing   the
                      difference   between  what's   wrong  and
                      what's right, what's illegal and legal.
             

                                         -67-
                                          67

            had some significant  credibility problems.  Consequently,  I

            cannot conclude beyond a reasonable doubt that the jury would

            have believed his  testimony; particularly in a  case such as

            this  where there  is absolutely  no physical  evidence tying
                                  _________________________________

            Trenkler  to  the bombing.   Cf.  Coppola,  878 F.2d  at 1571
                                         __   _______

            (discounting  inculpatory  testimony  of three  jail  inmates

            because  it "raises  serious  questions  of credibility"  and

            noting the absence of  any conclusive physical evidence tying

            the defendant to the  crime).  The only evidence  coming near

            thatlevelofreliability wastheimproperlyadmitted EXISevidence.

                      Absent the EXIS-derived evidence,  the government's

            case   against  Trenkler   consists  of   a   smorgasbord  of

            inconclusive  circumstantial  evidence   and  an   inherently

            unreliable  alleged jailhouse  confession.   Faced with  this

            sort  of evidence, a reasonable jury  would probably look for

            some  sort of tangible evidence  upon which to  hang its hat.

            The  EXIS-derived evidence was just that.  Because it was the

            only ostensibly  conclusive evidence  tying  Trenkler to  the

            crime,  it may  have been  the clincher  for the  jury.   See
                                                                      ___

            Coppola, 878 F.2d  at 1571.   It was  therefore not  harmless
            _______

            beyond a reasonable doubt.

                                          V.
                                          V.
                                          __

                      A horrible crime was  committed in which one police

            officer was  killed and  another seriously injured.   Society

            rightfully demands that the guilty be apprehended, tried, and

                                         -68-
                                          68

            punished.  But the distinguishing feature of our legal system

            is  that  even  those   charged  with  grotesque  crimes  are

            guaranteed certain  constitutional rights intended  to ensure

            that  they receive a fair trial.  Unfortunately, and with all

            due respect to  my brethren, I believe  the defendant's right

            to  a  fair  trial  was  violated  when  the  government  was

            permitted   to  introduce  the  highly  prejudicial  evidence

            derived from the EXIS computer database.   Because this error

            so severely  violated  defendant's Sixth  Amendment right  to

            confront the witnesses against him, and because the remainder

            of  the  evidence  against  him  was  not  "overwhelming,"  I

            dissent.

                                         -69-
                                          69