Blood Spatter Lecture

7/21/2019 Blood Spatter Lecture

1/116

Biological Fluid StainBiological Fluid Stain

Evidence: Blood and SemenEvidence: Blood and Semen

Lum FarrLum FarrDepartment Chair Criminal JusticeDepartment Chair Criminal Justice

Weatherford College ProfessorWeatherford College Professor

Forensic Science & Criminal JusticeForensic Science & Criminal Justice

AuthorAuthor

Forensic Investigation: behind the yellow tapeForensic Investigation: behind the yellow tape

Co-Founder and PresidentCo-Founder and President

A!"ICA# C"I! $C%&&LA!"ICA# C"I! $C%&&L


2/116


Evidence: Blood and SemenEvidence: Blood and Semen

Biological Material must beBiological Material must be

considered haardous!!!considered haardous!!!

Al"a#s $ollo" %niversal recautionsAl"a#s $ollo" %niversal recautions

$or handling stains'$or handling stains'


3/116

Blood and Semen EvidenceBlood and Semen Evidence

recautions used to collect biologicalrecautions used to collect biological

evidence:evidence:

(ear late) gloves* surgical mas+s* and(ear late) gloves* surgical mas+s* and

$ull coverage go"ns'$ull coverage go"ns'

E#e,coverings are needed $or collectingE#e,coverings are needed $or collecting

li-uid samples'li-uid samples' .eep hand out o$ areas that are hidden'.eep hand out o$ areas that are hidden'

/abel all blood samples/abel all blood samples


4/116

Blood and Semen EvidenceBlood and Semen Evidence

ac+age dr# samples in bags* as "ell asac+age dr# samples in bags* as "ell asstained clothing'stained clothing'

Add a note o$ precaution i$ biohaardsAdd a note o$ precaution i$ biohaards

li+e A0DS or hepatitis are suspected'li+e A0DS or hepatitis are suspected' Decontaminate all non,disposable items'Decontaminate all non,disposable items'

Destro# tags* $orms* or reports splashedDestro# tags* $orms* or reports splashed"ith blood'"ith blood'

Clean up hands "ith diluted bleach* andClean up hands "ith diluted bleach* anddispose o$ contaminated clothing'dispose o$ contaminated clothing'


5/116


Evidence: Blood and SemenEvidence: Blood and Semen1he term %niversal recautions means:1he term %niversal recautions means:

2ne must assume that an# biological2ne must assume that an# biologicalmaterial is contaminated "ithmaterial is contaminated "ithbiological pathogens such as 304*biological pathogens such as 304*3epatitis B* or others'3epatitis B* or others'

Al"a#s use protective clothing* e#e"ear*Al"a#s use protective clothing* e#e"ear*respirator mas+s* late) gloves* etc'respirator mas+s* late) gloves* etc'


6/116

5ature o$ Blood Evidence5ature o$ Blood Evidence

Blood ma# be encountered asBlood ma# be encountered as

ph#sical evidence in:ph#sical evidence in:

3omicides3omicides

Se)ual AssaultSe)ual Assault

4ehicular hit,and,run4ehicular hit,and,run

Burglar#Burglar#

2ther crimes2ther crimes


7/116

Bloodstain CharacteristicsBloodstain Characteristics

1raditional steps to $ollo" in tr#ing to1raditional steps to $ollo" in tr#ing to

describe various tests conducted:describe various tests conducted:

0s the sample blood60s the sample blood6

0s the sample animal blood60s the sample animal blood6

0$ animal blood* $rom "hat species60$ animal blood* $rom "hat species6

0$ human blood* "hat t#pe60$ human blood* "hat t#pe6

Can the se)* age* and race beCan the se)* age* and race be

determined6determined6


8/116

reliminar# Considerationsreliminar# Considerations

0t is essential to document* collect*0t is essential to document* collect*

and preserve blood evidence'and preserve blood evidence'

0mproperl# collected and preserved0mproperl# collected and preserved

blood evidence can "ea+en orblood evidence can "ea+en ordestro# a potential source o$ $acts indestro# a potential source o$ $acts in

a case'a case'


9/116


roperl# collected and preservedroperl# collected and preservedblood evidence can establish ablood evidence can establish astrong lin+ bet"een an individual andstrong lin+ bet"een an individual and

a criminal act'a criminal act'

Blood evidence or the lac+ o$ bloodBlood evidence or the lac+ o$ blood

evidence can bolster or contradict aevidence can bolster or contradict a"itness statement or an# statements"itness statement or an# statementsthe suspect ma# have made'the suspect ma# have made'


10/116


Blood evidence can point theBlood evidence can point the

investigator in the right direction $orinvestigator in the right direction $or

investigative purposesinvestigative purposes

0$ the evidence is collected and0$ the evidence is collected and

stored suitabl#* it can be presentedstored suitabl#* it can be presented

to a 7udge or 7ur# several #ears $romto a 7udge or 7ur# several #ears $rom

the time o$ the criminal act'the time o$ the criminal act'


11/116


erhaps the most po"er$ulerhaps the most po"er$ul

application o$ blood evidenceapplication o$ blood evidence

is the abilit# to absolutel#is the abilit# to absolutel#eliminate a person as aeliminate a person as a

potential suspect in a crime'potential suspect in a crime'


12/116


Communication is the +e# to e8ectivel#Communication is the +e# to e8ectivel#

processing blood evidence'processing blood evidence'

Clear and open communication must e)istClear and open communication must e)istbet"een a crime scene9s rst respondingbet"een a crime scene9s rst responding

o;cer* the case detective* the crimeo;cer* the case detective* the crime

scene investigator* the $orensic scientistscene investigator* the $orensic scientist

anal#ing the evidence and the assistantanal#ing the evidence and the assistant

district attorne# handling the case'district attorne# handling the case'


13/116


A crime scene investigator shouldA crime scene investigator should

+no" the crime lab9s capabilities* the+no" the crime lab9s capabilities* the

methods o$ blood collection andmethods o$ blood collection and

preservation pre$erred b# the crimepreservation pre$erred b# the crime

lab* the investigative in$ormationlab* the investigative in$ormation

relevant to the $orensic scientist* andrelevant to the $orensic scientist* and

the t#pe o$ re$erence samplesthe t#pe o$ re$erence samplesre-uired b# the crime lab're-uired b# the crime lab'


14/116


1his in$ormation can and "ill change1his in$ormation can and "ill change

periodicall# as technolog# changes*periodicall# as technolog# changes*

lab policies change* lab personnellab policies change* lab personnel

change* or lab administrationschange* or lab administrations

change'change'

1he pre$erence o$ $orensic scientists1he pre$erence o$ $orensic scientists

also ver# $rom lab to lab'also ver# $rom lab to lab'


15/116


0n the earl# ?9s most crime labs0n the earl# ?9s most crime labs

relied upon the AB2 blood groupingrelied upon the AB2 blood grouping

s#stem to characterie bloodstains's#stem to characterie bloodstains'

1his meant that the blood could have1his meant that the blood could have

come $rom @ to @= o$ thecome $rom @ to @= o$ the

population'population'


16/116


0n the


17/116


A crime scene investigator shouldA crime scene investigator should

+no" "hich method or methods o$+no" "hich method or methods o$

bloodstain anal#sis are availablebloodstain anal#sis are available

$rom his or her crime lab* the FB0 lab*$rom his or her crime lab* the FB0 lab*

and private labs in the communit#'and private labs in the communit#'


18/116


Currentl# bloodstain anal#sis $allsCurrentl# bloodstain anal#sis $alls

into three broad categories:into three broad categories:


19/116


1hese substances are more1hese substances are more

susceptible to degradation than D5Asusceptible to degradation than D5A

and this t#pe o$ testing usuall#and this t#pe o$ testing usuall#

re-uires a large -uarter siere-uires a large -uarter siesample in good condition $or optimalsample in good condition $or optimal

results'results'

1his t#pe o$ testing is rarel#1his t#pe o$ testing is rarel#

statisticall# individualiing'statisticall# individualiing'


20/116


Gestriction Fragment /ength Gestriction Fragment /ength

ol#morphism GF/ D5A Anal#sisol#morphism GF/ D5A Anal#sis

Direct anal#sis o$ certain D5A se-uencesDirect anal#sis o$ certain D5A se-uences

present in the "hite blood cells'present in the "hite blood cells'

D5A is much less susceptible toD5A is much less susceptible todegradation than proteins* en#mes* anddegradation than proteins* en#mes* and

antigens'antigens'


21/116


GF/ D5A testing is commonl#GF/ D5A testing is commonl#

statisticall# individualiing one out o$statisticall# individualiing one out o$

several million or billion and it hasseveral million or billion and it has

"ithstood rigorous court challenges on"ithstood rigorous court challenges onits validit#'its validit#'

1his method also usuall# re-uires a1his method also usuall# re-uires a

large sample sie to obtain signicantlarge sample sie to obtain signicant

results'results'


22/116


H ol#merase Chain Geaction CG D5AH ol#merase Chain Geaction CG D5A

Anal#sis:Anal#sis:

Anal#sis o$ certain D5A se-uences that haveAnal#sis o$ certain D5A se-uences that havebeen copied multiple times to a detectablebeen copied multiple times to a detectable

level'level'

CG based testing "or+s "ell on degradedCG based testing "or+s "ell on degraded

samples and small samples pinhead sie'samples and small samples pinhead sie'


23/116


Currentl#* it is not as statisticall#Currentl#* it is not as statisticall#individualiing as GF/ anal#sis'individualiing as GF/ anal#sis'

CG based technologies have alsoCG based technologies have also"ithstood rigorous court challenges on"ithstood rigorous court challenges onits validit#'its validit#'

Gecentl# there has been some concernsGecentl# there has been some concernsover the possibilit# o$ incidentalover the possibilit# o$ incidentalcontamination giving $alse results'contamination giving $alse results'


24/116


Follo"ing CG protocols should helpFollo"ing CG protocols should help

eliminate contamination thereb#*eliminate contamination thereb#*

eliminating $alse results'eliminating $alse results'

1he onl# "a# that $alse results "ere1he onl# "a# that $alse results "ere

reduced during studies* "as b# directreduced during studies* "as b# directcross contamination o$ "et samples'cross contamination o$ "et samples'


25/116


resentl#* the courts do not recognie bloodresentl#* the courts do not recognie blood

evidence as evidence that can beevidence as evidence that can be

absolutel# lin+ed to an individual* such asabsolutel# lin+ed to an individual* such as

ngerprints* bite mar+s* bro+en ngernails*ngerprints* bite mar+s* bro+en ngernails*and hand"riting'and hand"riting'

0$ D5A anal#sis is utilied* then blood0$ D5A anal#sis is utilied* then blood

evidence $alls into the categor# o$ evidenceevidence $alls into the categor# o$ evidencethat can be lin+ed to an individual "ith athat can be lin+ed to an individual "ith a

ver#ver# high degree of probability'high degree of probability'


26/116


GF/ D5A Anal#sis has been givenGF/ D5A Anal#sis has been given

the misnomer D5A Fingerprinting'the misnomer D5A Fingerprinting'

1he courts have since ruled that a1he courts have since ruled that a

D5A results can onl# be given inD5A results can onl# be given instatistical terms'statistical terms'


27/116


A Forensic Scientist cannot testi$# that aA Forensic Scientist cannot testi$# that a

bloodstain came $rom a specicbloodstain came $rom a specic

individual'individual'

3eIshe can testi$# that based on population3eIshe can testi$# that based on population

studies* onl# one person in several million orstudies* onl# one person in several million or

billion has a particular D5A prole'billion has a particular D5A prole'

3eIshe can then testi$# i$ the suspect or a3eIshe can then testi$# i$ the suspect or a

victim has that D5A prole'victim has that D5A prole'


28/116


Be$ore a crime scene investigatorBe$ore a crime scene investigator

begins documenting and collectingbegins documenting and collecting

blood evidence* heIshe mustblood evidence* heIshe must

recognie the value o$ bloodrecognie the value o$ blood

evidence and ho" it ts in the overallevidence and ho" it ts in the overall

events associated "ith the crime'events associated "ith the crime'


29/116


1he most common applications o$1he most common applications o$

blood evidence are:blood evidence are:

Finding blood "ith the victim9s geneticFinding blood "ith the victim9s genetic

mar+ers AB2 blood t#pe* D5A prole*mar+ers AB2 blood t#pe* D5A prole*

etc on the suspect* on something in theetc on the suspect* on something in the

suspect9s possession* or somethingsuspect9s possession* or somethingassociated "ith the suspect such as theassociated "ith the suspect such as the

suspect9s ngerprints'suspect9s ngerprints'


30/116


Finding blood "ith the suspect9s geneticFinding blood "ith the suspect9s genetic

mar+ers on the victim* on something inmar+ers on the victim* on something in

the victim9s possession* or somethingthe victim9s possession* or somethingassociated "ith the victim'associated "ith the victim'


31/116


2ccasionall#* investigator9s blindl# collect2ccasionall#* investigator9s blindl# collect

blood samples $rom a scene "ithout an#blood samples $rom a scene "ithout an#

thought about the $acts the# are tr#ing tothought about the $acts the# are tr#ing to

establish or the tests that "ill beestablish or the tests that "ill be$orthcoming "ith the blood evidence'$orthcoming "ith the blood evidence'

1he CS0 must ma+e an e8ort to collect the1he CS0 must ma+e an e8ort to collect the

evidence that is going to provide the mostevidence that is going to provide the mostuse$ul in$ormation in establishing the $actsuse$ul in$ormation in establishing the $acts

about a crime scene'about a crime scene'


32/116

BloodspatterBloodspatter


33/116


1he CS0 should concentrate on collecting1he CS0 should concentrate on collectingsamples o$ peripheral bloodstains'samples o$ peripheral bloodstains'

Blood a"a# $rom the bod# and the mainBlood a"a# $rom the bod# and the mainarea o$ action'area o$ action'

Blood spatter patterns that di8er $rom theBlood spatter patterns that di8er $rom the

ma7orit# o$ the blood spatter patterns'ma7orit# o$ the blood spatter patterns'

Blood trails leading a"a# $rom the scene'Blood trails leading a"a# $rom the scene'


34/116

eripheral Bloodstains A"a#eripheral Bloodstains A"a#

$rom Bod#$rom Bod#

B oo spatter patterns t atoo spatter patterns t at


35/116

B oo spatter patterns t atoo spatter patterns t atloo+ di8erent at the crimeloo+ di8erent at the crime

scenescene


36/116

Blood 1rails A"a# From Bod#Blood 1rails A"a# From Bod#


37/116


Because blood anal#sis is a comparisonBecause blood anal#sis is a comparisonanal#sis* re$erence blood samples areanal#sis* re$erence blood samples areneeded $rom the victim and suspect'needed $rom the victim and suspect'

A comparison must be made bet"een theA comparison must be made bet"een thegenetic mar+ers in the victim9s blood andgenetic mar+ers in the victim9s blood andthe suspect9s blood'the suspect9s blood'

1he blood samples $rom the crime scene1he blood samples $rom the crime scenecan then be anal#ed $or genetic mar+erscan then be anal#ed $or genetic mar+ersthat are di8erent in the suspect and victim'that are di8erent in the suspect and victim'


38/116


Suitable re$erence samples must beSuitable re$erence samples must be

collected $rom all involved and sentcollected $rom all involved and sent

to the crime lab'to the crime lab'

An unsuitable re$erence sample isAn unsuitable re$erence sample is

blood# clothing or some other blood#blood# clothing or some other blood#

item'item'


39/116


1hese are unsuitable because o$ the1hese are unsuitable because o$ the

-uestionable histories o$ the stains-uestionable histories o$ the stains

and there ma# be $actors present onand there ma# be $actors present on

the items that "ill give misleadingthe items that "ill give misleadingresults'results'

Samples must be collected inSamples must be collected in

suitable 4acutainers'suitable 4acutainers'


40/116


4acutainer usage:4acutainer usage:

ello" 1op 4'ello" 1op 4' %se$ul $or conventional serological testing%se$ul $or conventional serological testing

and D5A testing' personal pre$erenceand D5A testing' personal pre$erence

urple 1op 4'urple 1op 4'%se$ul $or D5A testingK ma# inhibit%se$ul $or D5A testingK ma# inhibitcertain conventional serological tests'certain conventional serological tests'


41/116


"ed (op )'"ed (op )'

*seful for conventional serological tests:*seful for conventional serological tests:

Less useful for +#A testing:Less useful for +#A testing:

Can be used for pregnancy and %I) testing:Can be used for pregnancy and %I) testing:

,ray (op )',ray (op )'

*seful for toicological testing.*seful for toicological testing.

#ot suitable for conventional serological#ot suitable for conventional serologicalanalysisanalysis

ay not be suitable for +#A analysisay not be suitable for +#A analysis


42/116


43/116


0$ collecting blood $rom an Autops#*0$ collecting blood $rom an Autops#*

collect one o$ each t#pe o$collect one o$ each t#pe o$

4acutainer'4acutainer'

Should be stored in a re$rigerator notShould be stored in a re$rigerator not

$roen at about $our degrees Centigrade$roen at about $our degrees Centigrade

until transported to the crime lab'until transported to the crime lab'

Bl d Bl d tt tt


44/116

Bloodspatter atternsBloodspatter atterns

ro7ected Bloodro7ected Blood

B oo spatter atterns B oooo spatter atterns oo


45/116

B oo spatter atterns B oooo spatter atterns oodroplets $rom di8erentdroplets $rom di8erent

anglesangles


46/116

assive Blood Dropletsassive Blood Droplets


47/116

1rans$er Blood attern1rans$er Blood attern


48/116

1rans$er Bloodstains1rans$er Bloodstains

i Bl d t i $ i Bl d t i $


49/116

assive Bloodstain $rom aassive Bloodstain $rom a

(eapon(eapon


50/116

Dripped BloodDripped Blood


51/116

Spilled BloodSpilled Blood

7 t d Bl d th hro7ected Blood through a


52/116

ro7ected Blood through aro7ected Blood through a

S#ringeS#ringe


53/116

Arterial SpurtILushArterial SpurtILush


54/116

Cast,28 StainsCast,28 Stains

0mpact Spatter /o0mpact Spatter /o"


55/116

0mpact Spatter /o"0mpact Spatter /o"

4elocit#4elocit#


56/116

Medium 4elocit#Medium 4elocit#


57/116

3igh 4elocit#3igh 4elocit#


58/116

Blood Evidence roblems:Blood Evidence roblems:

Communication bet"een CS0 and FSCommunication bet"een CS0 and FS

%n$amiliarit# "ith the t#pes o$%n$amiliarit# "ith the t#pes o$

bloodstain anal#sisbloodstain anal#sis

/ac+ o$ +no"ledge about "hich/ac+ o$ +no"ledge about "hich

stains "ill #ield the most use$ulstains "ill #ield the most use$ul

in$ormation'in$ormation'

oor re$erence samples'oor re$erence samples'

0ndiscriminatel# using /uminol at CS'0ndiscriminatel# using /uminol at CS'


59/116


1he identit# and t#ping o$ bloodstains can1he identit# and t#ping o$ bloodstains can Assist in establishing elements o$ the crimeAssist in establishing elements o$ the crime

Can identi$# or eliminate a suspectCan identi$# or eliminate a suspect

Can be used to corroborate or dispute theCan be used to corroborate or dispute thestatements o$ principals "hen the bloodstainsstatements o$ principals "hen the bloodstainspla# a part in a reconstruction o$ the crime'pla# a part in a reconstruction o$ the crime'

1he proper collection is essential to the1he proper collection is essential to the-uantit# and the -ualit# o$ in$ormation $rom-uantit# and the -ualit# o$ in$ormation $romthe stainsthe stains


60/116


Bloodstain evidence has t"o primar#Bloodstain evidence has t"o primar#

categories o$ e)aminationcategories o$ e)amination

importance to the crime sceneimportance to the crime scene

investigator:investigator:

A' Bloodstain pattern interpretationA' Bloodstain pattern interpretation

B' Lenetic Mar+er 1#pingB' Lenetic Mar+er 1#ping


61/116

Blood attern 0nterpretationBlood attern 0nterpretation

2$ten overloo+ed b# both the2$ten overloo+ed b# both the

investigator and the laborator#investigator and the laborator#

personnel'personnel'

0n man# cases the blood pattern0n man# cases the blood pattern

interpretation is more signicantinterpretation is more signicant

than the t#ping o$ the stains'than the t#ping o$ the stains'


62/116


63/116


Ma# establish "hether or not a crimeMa# establish "hether or not a crimeoccurred murder vs' suicide or accidentoccurred murder vs' suicide or accident

Ma# dispute or corroborate "itnesses9Ma# dispute or corroborate "itnesses9statements'statements'

Can determined $rom "hom theCan determined $rom "hom thebloodstain pattern emanated' geneticbloodstain pattern emanated' geneticmar+er t#pingmar+er t#ping


64/116


roper documentation o$ the locationroper documentation o$ the location

and patterns o$ the bloodstains shouldand patterns o$ the bloodstains should

al"a#s be a primar# consideration o$al"a#s be a primar# consideration o$

the crime scene investigator at athe crime scene investigator at acrime scene'crime scene'

Collection should 521 be attemptedCollection should 521 be attempteduntil the patterns have been recorded'until the patterns have been recorded'


65/116


66/116


All bloodstains should be recorded:All bloodstains should be recorded: 0n the 0nvestigators 5otes0n the 0nvestigators 5otes

1here should be crime scene s+etches1here should be crime scene s+etches

1here should be photographs1here should be photographs

1his "ill prevent a later attempt to interpret1his "ill prevent a later attempt to interpretthe pattern "ithout proper documentation'the pattern "ithout proper documentation'


67/116


1he location* sie* and1he location* sie* and

appearance o$ the patternsappearance o$ the patterns

must be care$ull# measured*must be care$ull# measured*s+etched* and photographeds+etched* and photographed

"ith measuring scales in the"ith measuring scales in the

photographs'photographs'


68/116


69/116


4ideotaping blood evidence can sho"4ideotaping blood evidence can sho"

the overall blood spatter patterns andthe overall blood spatter patterns and

ho" these spatters are inter related'ho" these spatters are inter related'

4ideotaping can sho" the relationship4ideotaping can sho" the relationship

o$ the spatters to the variouso$ the spatters to the various

structures at the crime scene'structures at the crime scene'


70/116


4ideotaping can be used to document an#4ideotaping can be used to document an#

blood trails leading a"a# $rom the scene'blood trails leading a"a# $rom the scene'

0ndoors videotaping can sho" ho" the0ndoors videotaping can sho" ho" thevarious areas are laid out in relation tovarious areas are laid out in relation to

each other and ho" the# can beeach other and ho" the# can be

accessed'accessed'

4aluable "hen recording peripheral4aluable "hen recording peripheral

bloodstainsbloodstains


71/116


0t is absolutel# essential that still0t is absolutel# essential that stillphotos be ta+en'photos be ta+en'

(hen available use* color(hen available use* colorprintsIslides and blac+ & "hite lm'printsIslides and blac+ & "hite lm'

0n$rared lm can also be used $or0n$rared lm can also be used $ordocumenting bloodstains on dar+documenting bloodstains on dar+sur$aces'sur$aces'


72/116


A good techni-ue $or recording large areasA good techni-ue $or recording large areaso$ blood spatter on a "all:o$ blood spatter on a "all:

Measure and record the heights o$ some o$ theMeasure and record the heights o$ some o$ theindividual blood spatters'individual blood spatters'

hotograph the overall blood spatter "ith slidehotograph the overall blood spatter "ith slidelm using a #ard stic+ as a measuring device'lm using a #ard stic+ as a measuring device'

Can be pro7ected onto a blan+ "all or theCan be pro7ected onto a blan+ "all or theoriginal "all later a$ter cleanup'original "all later a$ter cleanup'

0mpact Angle o$ Blood0mpact Angle o$ Blood


73/116


DropletDroplet



74/116


Droplet ,dimensional planeDroplet ,dimensional plane


75/116


Al"a#s dra" a CS s+etch'Al"a#s dra" a CS s+etch'

hotos are ,dimensionalhotos are ,dimensional

1he CS is H,dimensional1he CS is H,dimensional

hotos can distort spatial relationshipshotos can distort spatial relationships

Computer programs are no" available $orComputer programs are no" available $or

s+etching's+etching'


76/116


Chain,o$,Custod# $orm'Chain,o$,Custod# $orm'

0t is a "ritten record o$ all evidence0t is a "ritten record o$ all evidence

trans$ers $rom the CS to possession o$ thetrans$ers $rom the CS to possession o$ thecourt or the cler+ o$ court'court or the cler+ o$ court'

1he Chain,o$,Custod# thoroughl#1he Chain,o$,Custod# thoroughl#

documents the movement o$ evidence* thedocuments the movement o$ evidence* thesecurit# o$ evidence* "ho had possession o$securit# o$ evidence* "ho had possession o$the evidence* and "hen the evidence "as inthe evidence* and "hen the evidence "as ina person9s possession'a person9s possession'


77/116

/uminol 1esting/uminol 1esting

/uminol is a visualiation enhancing/uminol is a visualiation enhancing

chemical'chemical'

(hen applied to bloodstains* even ver#(hen applied to bloodstains* even ver#

diluted bloodstains* "ill cause thediluted bloodstains* "ill cause the

bloodstains to glo" in the dar+'bloodstains to glo" in the dar+'

Dra"bac+s should be a last resort $orDra"bac+s should be a last resort $or

the CS0the CS0

i l i


78/116


1he roblems "ith /uminol:1he roblems "ith /uminol:

2ne o$ the empirical tests $or determining i$2ne o$ the empirical tests $or determining i$

a stain is blood is its appearance'a stain is blood is its appearance'

0$ it is a bloodstain* it should loo+ li+e blood'0$ it is a bloodstain* it should loo+ li+e blood'

Blood should be present in su;cientBlood should be present in su;cient-uantit# to per$orm conrmator# testing-uantit# to per$orm conrmator# testingand genetic mar+ers'and genetic mar+ers'

i l i


79/116


/uminol is* at best* a presumptive/uminol is* at best* a presumptive

test $or blood'test $or blood'

0$ the stain is so dilute that it can0$ the stain is so dilute that it can

onl# be visualied "ith luminol* thenonl# be visualied "ith luminol* then

no $urther anal#sis can be per$ormedno $urther anal#sis can be per$ormed

to conrm the presence o$ blood'to conrm the presence o$ blood'

/ i l 1 i


80/116


/uminol "ill give $alse reactions'/uminol "ill give $alse reactions' Can react "ith copper ions* copperCan react "ith copper ions* copper

compounds* iron compounds* and cobaltcompounds* iron compounds* and cobaltions'ions'

0t "ill react "ith potassium permangante0t "ill react "ith potassium permangante$ound in some d#es and h#drated sodium$ound in some d#es and h#drated sodiumh#pochlorite bleach'h#pochlorite bleach'

Ferric#anide and plant pero)idases couldFerric#anide and plant pero)idases couldalso give $alse reactions'also give $alse reactions'

i l i/ i l 1 ti


81/116


Studies have sho"n that luminol "ill causeStudies have sho"n that luminol "ill causethe loss o$ several genetic mar+ers'the loss o$ several genetic mar+ers'

Because luminol is "ater based* it couldBecause luminol is "ater based* it couldcause* latent* possibl# blood# impression tocause* latent* possibl# blood# impression tosmear'smear'

/uminol could also $urther dilute an alread#/uminol could also $urther dilute an alread#diluted stain' 1his ma# push the staindiluted stain' 1his ma# push the stainbe#ond the gentic mar+er anal#sis detectionbe#ond the gentic mar+er anal#sis detectionlimits'limits'

i l i/ i l 1 ti


82/116


%n$ortunatel# some crime scenes use%n$ortunatel# some crime scenes use/uminol as their rst choice $or/uminol as their rst choice $or

detecting blood'detecting blood'

1his could cause loss o$ valuable1his could cause loss o$ valuable

in$ormation $rom a bloodstain'in$ormation $rom a bloodstain'

First choice should be high intensit# light'First choice should be high intensit# light'

/ i l 1 i/ i l 1 ti


83/116


Bloodstains are not eas# to eradicate'Bloodstains are not eas# to eradicate' Diluted blood "ill o$ten leave a bro"nishDiluted blood "ill o$ten leave a bro"nish

stain "hen cleanup is attempted'stain "hen cleanup is attempted'

3as a tendenc# to o" into oorboards3as a tendenc# to o" into oorboardscrac+s* carpet padding* behindcrac+s* carpet padding* behindbaseboards* etc'baseboards* etc'

1hese can usuall# be $ound using a high1hese can usuall# be $ound using a highintensit# light'intensit# light'

/ i l 1 ti/ i l 1 ti


84/116


Because /uminol is so sensitive toBecause /uminol is so sensitive tobloodstains* it is occasionall# used tobloodstains* it is occasionall# used to

enhance blood# impressionsenhance blood# impressions

shoeprint* ngerprint* etc'shoeprint* ngerprint* etc'

5ot the best method ho"ever*5ot the best method ho"ever*

because it is "ater,based'because it is "ater,based'

Collection and reservationCollection and reservation


85/116


o$ Blood Evidenceo$ Blood Evidence Most items o$ blood evidence "ill beMost items o$ blood evidence "ill be

collected in clean* unused papercollected in clean* unused paper

containers such as pac+ets*containers such as pac+ets*

envelopes* and bags'envelopes* and bags'

Can use plastic containers $or up to ,Can use plastic containers $or up to ,

hours'hours' 0 do not recommend an# plastic containers'0 do not recommend an# plastic containers'



86/116


o$ Blood Evidenceo$ Blood Evidence .e# note:.e# note:

Do not allo" an# evidence* especiall#Do not allo" an# evidence* especiall#

blood evidence to become contaminatedblood evidence to become contaminated"ith other evidence at the crime scene"ith other evidence at the crime sceneor during transportation to the crime lab'or during transportation to the crime lab'

Gemove blood evidence $rom the CSGemove blood evidence $rom the CSimmediatel# and i$ "et allo" to air dr# atimmediatel# and i$ "et allo" to air dr# atroom temperature'room temperature'



87/116


o$ Blood Evidenceo$ Blood Evidence %5DEG 52 C0GC%MS1A5CES S32%/D%5DEG 52 C0GC%MS1A5CES S32%/D

E40DE5CE C251A0505L M20S1%GE BEE40DE5CE C251A0505L M20S1%GE BE

SEA/ED 05 /AS10C 2G AEGSEA/ED 05 /AS10C 2G AEG

C251A05EGS F2G M2GE 13A5 1(2C251A05EGS F2G M2GE 13A5 1(232%GS'32%GS'

Moisture allo"s the gro"th o$Moisture allo"s the gro"th o$microorganism that can destro# or altermicroorganism that can destro# or alter

evidence'evidence'



88/116

Collection and reservationCo ec o a d ese a o

o$ Blood Evidenceo$ Blood Evidence An# evidence that can crossAn# evidence that can cross

contaminate each other must becontaminate each other must be

pac+aged separatel#'pac+aged separatel#'

Containers should be closed andContainers should be closed and

secured to prevent the mi)ture o$secured to prevent the mi)ture o$

evidence during transportation'evidence during transportation'



89/116

Collection and reservationo$ Blood Evidenceo$ Blood Evidence

Each container should have theEach container should have the

collecting person9s initials* the datecollecting person9s initials* the date

and time it "as collected* a completeand time it "as collected* a completedescription o$ the evidence anddescription o$ the evidence and

"here it "as $ound* and the"here it "as $ound* and the

investigating agenc#9s name and leinvestigating agenc#9s name and lenumberIcase number'numberIcase number'



90/116

Collection and reservationo$ Blood Evidenceo$ Blood Evidence

Be$ore transporting* e)amine the itemsBe$ore transporting* e)amine the itemsto determine i$ there is an# loose traceto determine i$ there is an# loose traceevidence hairs* bers* paint chips* etcevidence hairs* bers* paint chips* etc

that ma# be lost in transportation'that ma# be lost in transportation'

Collect this evidence in a paper pac+etCollect this evidence in a paper pac+etand place in an envelope'and place in an envelope'

Live description that matches the originalLive description that matches the originalevidence "here collected'evidence "here collected'



91/116

Co ec o a d ese a oo$ Blood Evidenceo$ Blood Evidence

Blood evidence must never beBlood evidence must never bee)posed to heat or humidit#'e)posed to heat or humidit#'

0$ possible* al"a#s re$rigerate until it0$ possible* al"a#s re$rigerate until it

can be transported'can be transported'

1a+e blood evidence to the lab as1a+e blood evidence to the lab as

soon as possible'soon as possible'

C ll ti D i d Bl d t iCollecting Dried Bloodstains


92/116

Collecting Dried BloodstainsCollecting Dried Bloodstains

0$ small and transportable* pac+age it'0$ small and transportable* pac+age it' AdvantageAdvantage

Minimal interaction "ith stain b# investigator'Minimal interaction "ith stain b# investigator'

Allo"s serologist to ma+e the decisionsAllo"s serologist to ma+e the decisionsinvolved in collecting the samplesinvolved in collecting the samples

Dilution and contamination potentialDilution and contamination potentialminimied b# eliminating "ater as theminimied b# eliminating "ater as thecollection medium'collection medium'

Disadvantage:Disadvantage: Bul+# items re-uire more storage space'Bul+# items re-uire more storage space'

C ll ti D i d Bl d t iCollecting Dried Bloodstains


93/116


/arge 0tems "ith stains:/arge 0tems "ith stains: Cut out a portion o$ the item "ith theCut out a portion o$ the item "ith the

stain'stain'

Cut out sample portion a"a# $rom stain'Cut out sample portion a"a# $rom stain'

Advantage: Dilution and contaminationAdvantage: Dilution and contaminationminimied'minimied'

Disadvantage: Must decide "hich stainsDisadvantage: Must decide "hich stainsand controls to collect'and controls to collect'



94/116


1ape /i$ting Bloodstain:1ape /i$ting Bloodstain: AdvantageAdvantage

Dilution and contamination potentialDilution and contamination potential

minimied'minimied'

5egative control is readil# collected'5egative control is readil# collected'

Ge-uires little storage spaceGe-uires little storage space

Eas# to per$ormEas# to per$orm

DisadvantageDisadvantage Must decide "hich stains to collect'Must decide "hich stains to collect'



95/116


Scraping bloodstains into a paperScraping bloodstains into a paperpac+et:pac+et: AdvantageAdvantage

Dilution and contamination potential minimied'Dilution and contamination potential minimied'

DisadvantageDisadvantage Must decide "hich stains to collectMust decide "hich stains to collect

Stains tend to brea+ into small* hard to handleStains tend to brea+ into small* hard to handlea+esa+es

Fla+es tend to get lost easil#'Fla+es tend to get lost easil#'

Some sur$aces are not easil# scraped'Some sur$aces are not easil# scraped'



96/116


Absorbing stains onto moist N longAbsorbing stains onto moist N longthreadsthreads AdvantageAdvantage

Stains are concentrated onto a small areas'Stains are concentrated onto a small areas'


DisadvantageDisadvantage

Dilution and contamination problem increases'Dilution and contamination problem increases' Must decide "hich stain to collect'Must decide "hich stain to collect'

>? ethanol is best to use as a dilution'>? ethanol is best to use as a dilution'



97/116


Absorbing onto moist N O N CottonAbsorbing onto moist N O N CottonS-uareS-uare

AdvantageAdvantage

Stain on small area'Stain on small area' Easier to handle than treadsEasier to handle than treads


DisadvantageDisadvantage Dilution and contamination potential increased'Dilution and contamination potential increased'

(et Bloodstains(et Bloodstains


98/116


0$ the item is small:0$ the item is small: ac+age in paper bag'ac+age in paper bag'

Bring to a secured locationBring to a secured location

1a+e it out o$ bag and allo" to air dr#'1a+e it out o$ bag and allo" to air dr#'

Gepac+age in original bag'Gepac+age in original bag'

Ma# then place in additional dr# bag'Ma# then place in additional dr# bag'



99/116


Advantage:Advantage: Ge-uires minimal amount o$ interaction "ithGe-uires minimal amount o$ interaction "ith

stain'stain'


More "or+ $or serologistMore "or+ $or serologist

Bul+# items ta+e more storage roomBul+# items ta+e more storage room''



100/116


/arge 0tems:/arge 0tems: AdvantageAdvantage

Ge-uires little storage'Ge-uires little storage'

Fairl# eas# techni-ue to per$ormFairl# eas# techni-ue to per$orm Stain concentrated onto small sur$ace area'Stain concentrated onto small sur$ace area'


Must decide "hich stains and controls toMust decide "hich stains and controls tocollectcollect

Must have direct interaction "ith bloodstainMust have direct interaction "ith bloodstain

BloodstainsBloodstains


101/116


(et blood has more value than dried blood(et blood has more value than dried bloodbecause more tests can be run'because more tests can be run'

Blood begins to dr# a$ter H P minutes o$Blood begins to dr# a$ter H P minutes o$

e)posure to air'e)posure to air'

As it dries* it changes color to"ards Bro"n orAs it dries* it changes color to"ards Bro"n or

blac+'blac+'

Blood at a crime scene can be in the $orm o$Blood at a crime scene can be in the $orm o$

pools* drops* smears* or crusts'pools* drops* smears* or crusts'



102/116


ools o$ blood have more evidentiar#ools o$ blood have more evidentiar#value'value'

Drops o$ blood tell the height and angleDrops o$ blood tell the height and angle$rom "hich the blood $ell'$rom "hich the blood $ell'

Blood that $alls perpendicular to the oorBlood that $alls perpendicular to the oor$rom a distance o$ ? $eet "ould ma+e$rom a distance o$ ? $eet "ould ma+ea circular drop "ith slightl# $ra#ed edges'a circular drop "ith slightl# $ra#ed edges'

Drops $rom a higher distance "ould haveDrops $rom a higher distance "ould havemore pronounced tendrils $ra#ing o8 themore pronounced tendrils $ra#ing o8 theedges sunburst pattern'edges sunburst pattern'


103/116



104/116


A blood smear on the "all or oor tells theA blood smear on the "all or oor tells thedirection o$ $orce o$ the blo"'direction o$ $orce o$ the blo"'

1he direction o$ $orce is al"a#s in the1he direction o$ $orce is al"a#s in thedirection to"ards the tail* or small end* o$direction to"ards the tail* or small end* o$

the smear* or splatter'the smear* or splatter' 0n other "ords* the largest area o$ the0n other "ords* the largest area o$ the

smear is the point o$ origin' "ave cast,o8smear is the point o$ origin' "ave cast,o8pattern'pattern'

Blood crusts need to be tested "ithBlood crusts need to be tested "ithcr#stalline methods to ma+e sure it9scr#stalline methods to ma+e sure it9sblood'blood'


105/116



106/116


Ge$rigerated red blood cells have aGe$rigerated red blood cells have ashel$ li$e o$ about @ da#s'shel$ li$e o$ about @ da#s'

1he serum containing "hite blood1he serum containing "hite blood

cells can be re$rigerated muchcells can be re$rigerated much

longer* almost up to a #ear'longer* almost up to a #ear'



107/116


D5A can be e)tracted $romD5A can be e)tracted $romblood i$ "hite blood cellsblood i$ "hite blood cells

"hich al"a#s contain a"hich al"a#s contain anucleus are present andnucleus are present and

also $rom sperm* bonealso $rom sperm* bone

marro"* tooth pulp* and hairmarro"* tooth pulp* and hairroots'roots'

Blood attern Anal#sisBlood attern Anal#sis


108/116


0mportance in the reconstruction o$ man#0mportance in the reconstruction o$ man#crime Scenes:crime Scenes:

0ndicates ho" the blood "as pro7ected $rom the0ndicates ho" the blood "as pro7ected $rom thebod# via several $actors'bod# via several $actors' 1#pe o$ in7uries1#pe o$ in7uries

1he order in "hich the "ounds "ere received1he order in "hich the "ounds "ere received

(hose blood is present(hose blood is present

1he t#pe o$ "eapon that caused the in7uries1he t#pe o$ "eapon that caused the in7uries

(hether the victim "as moved a$ter the in7ur#'(hether the victim "as moved a$ter the in7ur#'

3o" $ar the blood drops $ell be$ore hitting an ob7ect'3o" $ar the blood drops $ell be$ore hitting an ob7ect'



109/116


Blood ma# be dripped out* spra#edBlood ma# be dripped out* spra#ed$rom an arter#* ooed out through a$rom an arter#* ooed out through alarge "ound* or ung o8 a "eaponlarge "ound* or ung o8 a "eapon

raised to stri+e another blo"'raised to stri+e another blo"'

0n the


110/116


Drops on a horiontal sur$aceDrops on a horiontal sur$ace Splashes* $rom blood #ing throughSplashes* $rom blood #ing through

the air and hitting a sur$ace at anthe air and hitting a sur$ace at an

angle'angle' ools around the bod#* "hich canools around the bod#* "hich can

sho" i$ it9s been dragged'sho" i$ it9s been dragged'

Spurts $rom a ma7or arter# or veinSpurts $rom a ma7or arter# or vein Smears le$t b# movement o$ aSmears le$t b# movement o$ ableeding personbleeding person



111/116


Bloodstain pattern "ill help theBloodstain pattern "ill help theinvestigators understand the positionsinvestigators understand the positions

and means b# "hich the victim andand means b# "hich the victim and

suspect moved* interacted* andsuspect moved* interacted* andstruggled through the crime scene'struggled through the crime scene'

3elps to prevent an overabundance o$3elps to prevent an overabundance o$redundant blood samples $or D5A'redundant blood samples $or D5A'



112/116


1he shape o$ the blood drop can reveal1he shape o$ the blood drop can revealsignicant in$ormation'signicant in$ormation'

Leneral rule o$ thumb $or smooth* non,Leneral rule o$ thumb $or smooth* non,porous sur$ace might be:porous sur$ace might be:

Blood $alls short distance


113/116


Falls Q9 or more can produce small spurts that radiateFalls Q9 or more can produce small spurts that radiateout $rom the main drop'out $rom the main drop'

Man# drops less than an eighth o$ an inch across*Man# drops less than an eighth o$ an inch across*

"ith no larger drop* then it ma# be concluded that"ith no larger drop* then it ma# be concluded that

the blood spatter probabl# resulted $rom an impact'the blood spatter probabl# resulted $rom an impact'

0$ the source "as in motion "hen the blood lea+ed or0$ the source "as in motion "hen the blood lea+ed or

spurted* or i$ the drops e" through the air and hit anspurted* or i$ the drops e" through the air and hit an

angled sur$ace* the drops generall# loo+ li+eangled sur$ace* the drops generall# loo+ li+e

stretched,out e)clamation mar+s' 1he end o$ thestretched,out e)clamation mar+s' 1he end o$ the

stain "ith smallest blob indicates the direction instain "ith smallest blob indicates the direction in

"hich the source "as moving'"hich the source "as moving'



114/116


/eading Authorit# on blood stain/eading Authorit# on blood stain0nterpretation gives the $ollo"ing tips:0nterpretation gives the $ollo"ing tips:

0t is possible to determine the impact angle o$0t is possible to determine the impact angle o$blood on a at sur$ace b# measuring theblood on a at sur$ace b# measuring the

degree o$ circular distortion o$ the stain' 0ndegree o$ circular distortion o$ the stain' 0n

other "ords* the shape o$ the stain tends toother "ords* the shape o$ the stain tends to

change depending upon the angle o$ impactchange depending upon the angle o$ impact

"hich caused the stain' For e)ample* the more"hich caused the stain' For e)ample* the morethe angle decreases* the more the stain is lessthe angle decreases* the more the stain is less

circular and more long'circular and more long'



115/116


Sur$ace te)ture is one o$ the +e# components inSur$ace te)ture is one o$ the +e# components indetermining spatter t#pe' 1he harder the sur$acedetermining spatter t#pe' 1he harder the sur$ace

is* the more spatter "ill result' 0t is there$oreis* the more spatter "ill result' 0t is there$ore

e)tremel# important to duplicate the sur$ace in ae)tremel# important to duplicate the sur$ace in a

controlled test'controlled test'

(hen a droplet o$ blood hits a sur$ace "hich is(hen a droplet o$ blood hits a sur$ace "hich is

hard as "ell as smooth* the blood usuall# brea+shard as "ell as smooth* the blood usuall# brea+s

apart upon impact' 1his in turn causes smallerapart upon impact' 1his in turn causes smaller

droplets' 1he smaller droplets "ill continue todroplets' 1he smaller droplets "ill continue tomove in the same direction as the originalmove in the same direction as the original

droplet'droplet'

American Crime SchoolAmerican Crime School


116/116


For More 0n$ormation ContactFor More 0n$ormation Contact

/um Farr resident/um Farr resident


R,P=R,QHH CellR,H?>,@>H Cell $arr"c'edu$arr"c'edu

Documents

Blood Spatter Lecture