Phvsical Match of Fragmented Bullets

FireamrsLaboratorv-
CascRcirot't
PhvsicalMatch
of
FragmentedBullets
Authors:
Asne Klein
Lior Nedivi
Howard Silverwater
d LlllEls
P l r \ . i c r l \ l . r t c l lc l l t J p l n c , ! r e D
March1998
!'ircarrnsI.abrtraion
{lasc Rc (lrt
AsneKlein,l M. Sc.;Lior Nedii,2 B. Sc.:and Htnard Sil\etvatet,3 B. EngineeritY'
Physical Match of Fragmented Bullets
glass'
AISTRACT: Thetechniqueof physicalrnatch,whichis widelyusedwith naterialssuchasplaslicand
metho4of tool
of commonorigin. The moreconventional
bunetslor d€t€rmination
is appliedto ft'agmented
fuearm.
with
a
the
bullet
to
cotrnect
is
late.
used
mark comparison,
li! ftacturematch'{iagments
phlsicalmatch,physicalfit' mechanical
iorensicscienc€,
KEYVyORDST
Thetechdqueofphysicalrna6h'alsokrcwnasphysicalfit'mechanicalfitandftacfurematclrisoftenus€d
or more, fiagments of plastic, glass,m€tals
$ forensice:.1ertsin ordel to determinatea commonorigin ol two,
"the eraminadon of tso or mor€
glossary,
the
AFTE
malch
as
d€fined
[U
oi oOer sotsta"ces-nrysical
W
objeds either through physical, opticNl or photographic means wbich permib otre to conclude whether
thi objects were eitter oni entity or were neld or bond€dtogether in a udque Nrrangementz
The bigg€st advafiage ofthis t€chDrqueli€s in the fact tbat it is not necessaryto be an e\Tert to cometo the
"Physicrl fits and broken edger ff anlthing
conclusi; rbat there i; a physical match. WALLst2l wrole'
getsbmkenincommittingacrim€,andifoneofthesepartsfufound&tthescen€andtheolhercrnbe
"tioL"O
.itl
tne susXct, lh€n the fitting togethcr of tbe brok€n edges may pmvide th€ mos'
incontrov€rtible €videucepossible- eddence which n€edsno scie ific training for its rppreciation". H€
colweyedthe commonbelief amongforensicexlerts rhat this is the bestkini of evidence
'...*hetr the fragmedts show r physical fit of a
fi*
I:1 usea even sfionger words when he $roie,
fractured surface' such cvidorc€ b€ing ro strong a3 to constitute a|mogt rbso|ute pmol,. These wolds
emphasizethe importrnc€ of physical match in the world of forenslc science we should also rcmemtEr th€
judgqo and'/orjury, of the
reasonfor all this wotk, meaningour appeamtrceat court in order to convincethe
Israet,
wi[ show the etrect of
held
in
two
trials,
ftom
inportance ana weigfrt of o* *ia*ce' Quotatons
a random proc$s Nnd
brea|."fu
verdrcls:
?!$
phlsicat rnatch testimonywithjudges wh they write lheir
lin€_ As we know
x
similarlreak
p""ctical
ol
creating
way
cen tappen in inlinite wrys, but the"e i. oo
ii r connecfon
therc
lhat
I
rm
convrnced
ftot th;; rre no where i; the world two iltenticd fEgerprints,
Frcm another
carln
glars
pi€ces
from
the
def€ndatrt's
betweetr the glast pi€c€s fmm the sceneand the
demofftrat€d
who
"Th€
€lpert,
Tml
Mark
of
tbe
;dence brought beforc court, in ihe te3timony
tdal:
the
lhe match between the difr€rent phstic piecd, prov€ beyond any doubt the po$ibility to conn€ct
d€fendant's car to the scen€of ihe accident...'.
,ltthoogtr this techniqueis widely usealwhen hanalhngfiagmentsofplastic' glassand metal objects,it applies
equallywell with fi:.gmentedbuletsfmgmented
in tils anicle we-w t ldiscuss this problem and] gr€ two examplesof physical matchesof
only one
was
question
whether
there
of
the
bul€ts. Being abte to find such a match gave us the answer to
fir€arrn, or morc, in the incident.
rscientificofrcef, ToolMark andMaterialsLaboratory,
DivisionofldetrtificationandFofensicsciedce
Israel.
(DIFS),IsraelNationalPoliceHq Jerusalem,
)former fireannsoxaminerat DIFS.Duryofrcer, Allelby Bridgecrossingpoint,SHAYDisrrict'Israel
Na[onalPolice.
]FirearmsExaminer,FaearmsIdentificatron
LaboBtory,D rsionofldedt'iicationandFor€nsicscience
Israel
(DIFS),IsraelNationalPoliceHq Jerusalem,
Irhr,'sical\'1atchof aragrnelrtedlhll€ts
i r:i,:t\tncri
fii ':irill. i .li'rl:,il'r,'
Bullet trragmentation
When a bullet hits its target, it sometimesfiagments Tle fragmentationdepcndson the bulfel's caliber' tt?e'
irnpact velocity and trajectory within lhe urget. Bullets' like tlre caliber 9xl9 mm (9 mm Parabellum) with
gpical velocities of 35b meiersper sccond(1150 feet pcr second)can ftagment into lwo or more fragments
geat number of
Higher velocity bullels, such as the caliber 5 56x45 mm (5.56 NATO). ftagment into a
"snow storm"
fra-gnents,surting at velocities of gS0 metersper second(3220 feet per second),creating the
efect. See6gure I [6].
Vol-3107t/i
Vel32o4 ,/s
977 r'.'lt
$l:'.'&
i-+ '.'
v el-265o1/s
8o8 n/s
*ii;
Vel-2523 f/s
v al-262ot/s
799m/.
-- r'- ,1
r'.'l
s
v € l ' 2 3 9 5t / 5
73O rnls
v€l2OlOl/s
Vel 2139 ly'i
63? !nls
613 m/!
o&'''
Vel-1996
608
Y el-1674lls
510 n/s
Vsl-1616f/s
493 nilt
Vsl-!556 llr
474 nl/ t
&
Figure t - Impact velocity elT€clon bullet's fragmentatiotr'
Co iesr ofDr' M I' Fackter
crime scene The
On occasion,parts of the fragmentedbullets go through the body and are left ?t the
fragm€ntsfrom within
examinerwho ieceires this g'ideircc is requircdto determinc,amongother things' if the
firearms)
and outsidcofthe My originatedfrom a commonorigrn (namelyonc or morc bullcts and
Factors invohjedin phyncal natches
Gupta [7] sumrurizes the factorsinvolved in physical matches:
(a) The avemgeor generalthicl essofthe maEnal
O) The variations and irregularities in this thickness.
gencmlcolor.
(cl The -gencrat
shapeof rhc lrneof the Learor breatrr'e ziglag cun cd sraight etL
tdt The
Pll'sicil Maich o i fl ilqlrlclrtaiiEilllelri
FirearrnsLa
(e) Theinegulariti€sftom pointto pointalongtheline ofthe break.
(D The$riatioru, rib-marl$or iftIErfectionsalongthecross-sectronal
surfaces
ofthe brokenedge.
Whenexaminingbulletfi'agmenls,
weobEerved
thre€baslcmanneisofbr€akageGeparation):
t. Alongthe longiMinal axisofthe bullet.Usuallyalongthedrivingor trailing edgeofthe land
impressions,
howeverit canoccurin between
lhe landimpre$sions.
Seefigure2.
2. Atoftgthehorizonlalaxisforwardofthe landimpression.Seefigure5.
3. Alongthehorizontala\is - insid€thelandrllarksimpressions
s€ctroflor alonga cinnelure.
Also,bull€tbrealopcanoccurwith diferenl combinatio$of theaboveftarneN.
Whenencountering
melhodsto try to co recltwo
optionsI & 3, theexaminercanusetraditionalcomparison
or moref:agmefts Sucha comporisonneed6the "help' ofa completebullet for exanpleanother€rr'idence
On hh cases,he can conducta
bulet or a testbullet (if the examinerhasthe firearm in his poss€ssion).
The outconreof the
comporisonbetweeneachfiagmentto lhe test bullet's land and gmve impressions.
con@risonmight concludetbat bolh ftagmentswerefired ftom the samebarrel. Ho*€l€r, this doesnot
nec€ssary
neans thefragnentscomesfiom the samebullet.
ln optionnumber2, a conparisonwiil be evenmoredifficult sincethe upperpart of lhe bullet (wher€the
cannelures
arelocated)generallycontaina lowerquantityand qualityof bullet striae(individuatmarksfrom
thefireafin'sbanel).
tn a[ thesecagesa physicalmatchcanprove,beyondany doub! that two fiagmentscomefiom a common
origin,onebullet.Thefolowing examples
will showthat evenifone ofthe fragmentsis s€verelydamag€4it is
still possibleto geta physicalmatch.
CrseStudies
CaseI
ln tle courseof a drsputebet*€entwo gangs,seve.alshotswher€fir€d by a memberof one gang at
members
ofthe othergang.Onemanwasinjuredin his leg.
Recovered
at lhe crimescenewercfour 9 mm Short(9 x 17rnm)canridgecasesanda Fagtnflt ofa bullel
whichwasdelermined
at thefirearmslaboratory,
asa partof 9 Shonmm bulle! FMJq?e.
later, anotherfragmentof a bulleq swgicallyremovedftom lhe victim's leg wajl-segtto the firefims
laboratory.This piecewEsalsoidentifiedaspafl ofa 9 rnmShonFMJbullet.FigureTsho\ 4 baseviewof the
twof.agments,positionedsideby side.
\ 7
Figurc 2 - A ba!€ vi€w of the two fmgmeBts,
Dosition€dside by sideFMJ bu et caliber 9X17 n
Pl1'sicalMatchof FraEnertedBLrllets
I
FirearmsLaboratorv
CaseRenoft
Examinarion
of theevidences
discover€dthefollowingfacts:
pistol,mootprobablya Czechoslovakian
cz model
1. Thecartddgecaseswerefired ftom onesemi-automatrc
83,cdibergltrn Short.
alsoagre€with tho6eofthe CZ 83barrel.
2. Classchamcl€ristlcs
onbothfragm€nts
arca partof onebulel or originateftom
Thechiefinv€sligalorofthis casearl€d iftte twobr let fi:agments
question
in
to removeany dout'l aboutthe fact
ahe
to
this
was
unportant
order
diferent
bullets.
answer
two
ftat therewasonly oneshooteral thecrimescene,Inforsatronvilal to adwncethe investigationThetefore,
Thetearline on thebullet'seNelope,on boti t'aglrents,sas localedbetw€enland impressions.
striations.
of landirnpression
therewasno wayof comectingthemby meansof comporison
SincetherEwasnootherbulletrccovercdaadthepistolFasnotfoun4 theonly*ay to tie thet$! fiagm€ s
logetherwasby meansofphy6icalnatch.
microoco,pe
underhigh power
Theedgesof thebulet envelope's
basewereexamine4usingthecomparisotr
magnification.By briryitrg tliemlogsther,oneedgenextlo ils couflerparqit waspossibleto se€the physical
matchalongthetearline. S€efigues 3 and4. Thefnal e4ert reportstatedthat thetwo fragmentswercofone
hdlet.
In tiis case,a cerlain amountof "ac.obatic"denerity in hallding the two pieceson the clmparison
the rnalch lt required
in orderto positionthernin a waywhichxould empbasize
microdcope,
wrs necessary
stutE,thelight'sFsition andthe light'sanglebeforcthe ffatch
oanipulationofrhe oq,ectsotrthe microdcope's
microocope
tas used.
A labletopLei{zcomparison
became
appgrent.
figures 3&4 - Physicolmatchdong lhe terr lines
Cdse2
A climinal wasslain in broodday light. The DNrder€rshothim fte timeswith a Colf Cobra38 Special
revolver,the si{h bulletwasa misftr€dThevicti{r got{rp,ran Aom his attaclctbut dropFd in th€ middleof
mod€l39-2
Strith & We'sson
the street.At this point tle murderercam€clos€r,F led oula semi_altomatic
pislol
head
(9x19
him
once
rn
Oe
mm)
and
shot
Parabellum
9
Dm
caliber
one9x19mm cartddgecase,one38 Speciatlead
unit atrivedal the sc€oeaod col1ecled
The crims sc-ede
blllet aoda fragEentof a 9xl9 mm FMJbullel (Figures5&6) Later,two more38 Specialleadbulets ad
PhysicalMalch o{ [ragmentedBullets
aiotherfragmentofa 9x19mmFMJbullet(Figure€5&6)werercco!€r€dby lhe coronerdring the autopsyof
thevictim.
It *ts obviousthat at leasttwo fir€armswercinvolve4but the iN'€stigting teamneedEd
to knowifa lhird
fiIearm was involved It wasnecessary
to det€rmineif the t$o 9x19om fragmetrlscarneout of the sarre
barrel.It couldnot be donet'y meansof land and groo!€ impr€ssioncomparisons
sincethe fiIst fi'agment,
forlndat the scenq*€r theforwardsectionof the bulet andtherec,er no land ifiprcssionmark on it. The
only l'ay 10connectthi6 fragmentto a specificfrearm was ry firding som€aonnectionto the fragm€nt
ftom thebody.Amazilgy enoughtftoughthewo fragmentsweredEfonne4a ph'sical rnatchwas
rccovered
possible.SeeFigures5, 6 and7.
Iater in the investi9tio4 the semi-autorDatic
S&W 39-2 was recor€redand a comparisonwas maab
betElenthe 'rehilt" hrllet andtestbulets fircd Aomrhepistol.
Wlen the case*!s present€d
at courl the defensecounseloqectedto the p.ocessof physicalrnatchof the
bull€lfi'agInentsandrequ€slad
that thefragmeatsbecyaminedby his o*n €xper1.The trial end€dwith a plea
bargainandthis evidence
wasneverchallenged
trtgurtt 5&6 - Ph$ic&l mrtch of th€ two 9X19mm bullet frrgments.
o - Thefrognentfoundat thescene.
b TheI/agnent rccoveredflomthebody.
Figur€ 7 - IhFicsl match.
Closeiev oJthe tear line.
PhvsicalMatchof Frasmented
Builets
o
Laboratory
Firearms
Renort
Clase
Summary:
plr:rsicatmatcnes,bete/eenbulets i'agmclrts,can be a rery po*trfrn bol to the reams exanincr'
betseena bulet iagEenl atrd
it is the ody wayto €stablisha conneclron
i"*fog*a" ,ta ooutt".Sometimes
theftearm ii wasfir€dfotn-
Rcferemg:
ofFirr€nn andToolMark E (.rnirrers,AFTE f%9'
Ifl Gbssary,Associatiotr
Swe€!& Maxs€l Lidite4 Loadon'1968'Fp 14-15'
fote*i" Science",
izi Waff6,H. f.,'C.i^e
pp 300-301'
p.
I*€6tiptioa", second€dition'Joh! Wilery& Sonss
i:i K ., L.,
'rfac"t
ofForensicscieoce,vol 31,No'
N4atches,'
Joumal
Phrsical
Mod€ls
of
as
suac€s
i+i iloito", i f.,
1435-1438.
4 Oct 1986,F.;Oi."
I*"$igtion PIrysicalEvid.nceald thePolicetaboratory,"InteFciencePublishers'
tit Xi.t, p.i.,
INC.,NewYo*, P.240.
dsledMay 2l'
[6l F;rkhr, M. L.IvfD., F.AC.S.,WoundBalistic Crnsd!trt, PeconnelConesFrd€nce
InterlationalCriminstPouceRwiew,tune-Julv1970'p 198-200
of Fragmeots,"
,.*, *,*,
ii'k*
"Tech"iq,tes
of CrimeSceneldve6tigation"4th 6dition''p' E'
iAt fiOer, S. J,
PhysicalMatchof FlagmeltedBulleis
7
J