fs final exam review 2013.doc

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Forensic Science: Final Exam Review

Unit 1: Crime Scene Investigation

Forensic Science: The study and application of science to matters of the law

Physical Evidence: n o!"ect or su!stance that is used to prove elements of acrime

Testimonial Evidence: ver!al account of events or details of a crime given !y awitness and#or e$pert

Circumstantial Evidence: Evidence that is collected %either physical or testimonial&that is used INDIRECTLYto prove elements of a crime' This type of evidence ()ES*)T P+),E -UI.T/

E$pert 0itness: person who is specially trained and certied in an area thatallows him or her to testify in court %i'e' 2edical E$aminer3 4lood Spatter E$pert&

The Frye Standard: E$pert opinion !ased on a scientic techni5ue is admissi!leonly where the techni5ue is generally accepted as relia!le in the relevant scienticcommunity %The 6-eneral cceptance +ule7&

The (au!ert Standard: Scientic techni5ue admissi!le in court if it is:

o Testa!leo Peer8+eviewed

o +ate of Error must !e given %e$ception to rule 9: ngerprints&

2iranda +ights: +ights that are guaranteed !y the Constitution of the United Statesof merica' n individual 2UST !e read his or her rights prior to !eing arrested'

o +ight to remain silent

o nything you say can and will !e used against you

o +ight to an attorney

o If you cannot a;ord an attorney3 one will !e appointed to you

o If you answer 5uestions without an attorney3 you have the right to stop

Pro!a!le Cause: The standard !y which an o


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?elp anyone who is in"ured

Process the crime scene

(ocumentationo Photographs

s many as possi!le//

)verall views3 2edium views3 Close8up views

o S=etches

Floor plan %64ird>s Eye ,iew& Triangulation 2easurements %for +econstruction purposes&

o *otes

)!servations using .. of your senses %e$cept taste//&

Conduct a systematic Search

o Spiral

)utdoors3 wooded area

o @uadrant#Aone

Car#,ehicle

o .ine#Strip

)pen Fieldo -rid

Indoor room#warehouse

Collect3 pac=age3 and la!el evidence properly/

o 4iological evidence

2ust !e dried C)2P.ETE.B and then pac=aged in a !reatha!le !ag

or envelope'o Trace evidence

Tape8lifted3 then pac=aged in !reatha!le !ag or envelope

o rson and e$plosive evidence

Contained in an air8tight canister %metal#plastic& I22E(ITE.B/ (on>t forget to collect C)*T+). S2P.ES//

o se$ual assault cases

victim%s&3 suspect%s&3 se$ual partner%s&

o homicides

victim%s&3 suspect%s&3 others who have !een in contact with CS

o hit8and8run accidents

glass3 paint3 plastic3 tire prints from suspect>s car

o !ra=ing8and8entering

window glass3 paint3 tool mar=s from items within suspect>s

possession .egal Considerations: 2ust have a warrant to arrest and#or search U*.ESS:

Emergency Circumstances

In"ury (anger .ife8threatening circumstances

Prevent loss or destruction of evidence

6Dushing drugs down toilet7,E+B dis home3 o


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o (*

-+CF: -eneral +iDing Characteristics File

o Firearms

I4IS: Integrated 4allistics Identication System

o 4ulletproof: !ullet analysis

o 4rass Catcher: cartridge casing analysis

Unit G: Physical Evidence

Individual Evidence:

o Evidence that can !e lin=ed to )*E %1& individual source %i'e' person3 animal3

thing3&

Class Evidence:

o Evidence that can !e lin=ed to a group of sources %i'e' persons3 animals3

things3&

4iological Evidence:

o Physical evidence that IS&'(S&'(S FR)* a living thing

Trace Evidence:o E$tremely small or 6invisi!le7 physical evidence

-eneral Physical Evidence:o tangi!le item or su!stance that is used to prove any element#part of a

crime

(eductions from o!servations includeo Color3 appro$imate siHe3 te$ture3 smell3 shape3 '

E$aminations#Forensic nalyses includeo 2ass3 volume3 density3 thic=ness3 temperature3 microscopic3 refractive

inde$3 chromatography3 chemical analysis3 '

E$amples of E5uipment'o 4alance3 graduated cylinder3 microscope3 thermometer3 laser3 super glue

fuming cham!er3 gas chromatograph#mass spectrometer3 '

Unit : Trace Evidence

.ocard>s Principle: 6Every contact leaves a trace7

Transfer of Trace Evidence

o Primary: (irect Transfer %from Source to suspect#victim#crime scene&

o Secondary: Indirect Transfer %from source to intermediate carrier to S#,#CS&

Soil:o pplications:

)n Shoes

Tires

t the crime scene

)n victim and#or suspect

o nalysis: Color

Te$ture

-rain siHe

(ensity

?air: ppendage of the s=in that grows out of the hair follicle %an organ&

o Parts of ?air: 4ul!

+oot

Cuticle

Corte$

2edulla

Fi!ers: The smallest unit of a te$tile material that has a length many times greaterthan its diameter


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o Types: Natural: nimal or Plant source

Synthetic: 62an82ade7

o nalysis: Fi!er Structure

Comparison 2icroscope

Scanning Electron 2icroscope %SE2&

Cross8section of !er %triangular3 star8shaped& Fi!er Colors

2icrospectrophotometer

spectral patterns and 4ec=e lines

crystallinity

Thin .ayer Chromatography: separate components %colors& indyes

Fingerprints

The Scientifc Method

o

Identify a @uestiono -ather Information and +esources %+esearch the Pro!lem&

o Form a ?ypothesis#Suggest a Solution

o Test the ?ypothesis#Solution

o nalyHe (ata

o Interpret (ata#(raw Conclusions

88ccept or +e"ect ?ypothesis#Solution

o +e8test//

o +eport +esults#Pu!lish +esults

0hy the Scientic 2ethod

o 8To decrease !ias

o 8To provide a systematic3 consistent procedure %P+)T)C).&o 8To validate results % or more trials resulting in the same#similar data&

Fingerprints

o Who: All primates (including humans) have friction ridge patterns(fingerprints, palmprints,

footprints)

o What: Raised ridges and furrows that are designed to help grasp items

At the top of the ridges are sweat pores that release:

99% H2

!% oils, fatt" acids, esters, salts, urea, amino acids

#otal volume of ! adult fingerprint $ a few microliters (&)

o Where: n ever" surface that a person touches

#hree t"pes:

&atent ('invisile)

*atent+isile

*lastic (mold+cast of fingerprint)

o Why:

#wo Rules that allow us to use fingerprints for identification:

-ni.ue to ever" individual /including identical twins

*ermanent for an individual0s lifetimeo /friction ridge patterns are formed in the !2 th1!thwee3 of fetal

development

o /e4ceptions: scars and growth (si5e)

o When: 6ore li3el" to leave a lasting print when fingers are warm and perspiring (oil")

Categorizing and Analyzing Fingerprints

HENRY CLASSIFICATION

ACE-V


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o nalysis: @ualitative and @uantitative ssessment

o Comparison: greement or (iscrepancies !etween G ngerprints

o Evaluation: Consistent Inconsistent Inconclusive

o ,erication: second independent analysis3 comparison3 and evaluation !y

another 5ualied e$aminer'

Categorization

o Level 1: -eneral ridge8Dow

Pattern rch

.oop

0horl

o Level 2: Formations and com!inations

2inutiae Points

o Level 3: (etails within the formations dimensional attri!utes of a ridge

Unit J: 4iological Evidence

Sources of 4iological 2aterial:

o 4lood

o Semen

o Saliva

o Urine

o ?air3 Teeth3 4one3 Tissue

Types of Crimes Involving 4ody Fluids

o Se$ual ssaultso ssaults

o ?omicides

o 4urglaries

o (esecrations

Process of Forensic E$amination of Evidence

o +ecognition 60hat is important7 SC+EE*I*-#P+ESU2PTI,E TESTS

o Identication

60hat is it7 %class category& C)*FI+2T)+B TESTS

o IndividualiHation 60ho or 0hat did it come from7 %uni5ueness&

Serology: The study of !odily Duids using specic antigen and serum anti!odyreactions

Secretors: KLM of population have !lood antigens % N 4& in other !odily Duids

Types of 4odily Fluids: Urine3 Saliva3 Semen3 4lood

Urine: 0aste secreted !y the Oidneys

o 0ater3 salts3 inorganic ions3 and organic compounds %urea N creatinine&

o Tet:


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Hosti$: detects Urease

false %& for sweat3 semen3 vaginal secretion Qa;e Test: detects Creatinine also in sweat3 !ile3 gastrointestinal Duids

o T .EST R8GL m. necessary for!oi"le(* testing

Saliva: 'RM water3 and L'RM mi$ture of mucous3 inorganic ions3 proteins3epithelial cells

o Tet:

Phade!as Test3 Procion +ed mylopectin Test 4oth tests detect 8mylase %digestive enHyme& activity %8mylase is

found in plants and !acteria& lso found in: semen3 vaginal secretion3 serum3 feces3 perspiration3

!reast mil=

Semen: Seminal Fluid#Plasma SpermatoHoao Screening Tests:

U,#lternate .ight Source ,isualiHation

Fluorescence properties of J8methyl um!elliferyl phosphate%2UP& with Pase

Seminal cid Phosphatase %Pase& Test:

Fast 4lue 4 dye 8naphthyl8phosphate Pase is a ,ery sta!le enHyme %tested after GL years in dried stains&

Positive result:: insolu!le pin=#purple colored product

o Conrmatory Tests: 6Christmas Tree7 Staining %using microscope&

SpermatoHoa is stained red %head&3 green %middle&3 and yellow%tail&

!acus )ne Step 4 card pL Test

Prostate Specic ntigen %PS or PL& V human seminal Duid protein

that is secreted !y prostate gland

Positive result: dye8colored insolu!le !and on cardo IndividualiHation: (* Tests

o Se$ual ssault Crimes: Statistics and Information WK rapes#hr in US and #1L victims are female

KLM victims are under L years old %high ris=: 1G8J years old&

WXM of female victims =new their assailant

o 0hat to collect

8Clothing

84edding

8Fingernail#toenail scrapings3

8Com!ings %head and pu!ic hair& 84lood: within 1G8GJ hours after assault

8Urine: within X8WG hours after assault

8Semen: within GJ8JK hours after assault

J swa!s from each orice

()*>T F)+-ET C)*T+).S//

4lood:

o comple$ mi$ture of cells3 enHymes3 proteins3 and inorganic su!stances

o Components: 8#la$aV RRM of !lood

LM water 1LM meta!olites3 waste3 salts3 ions3 and proteins 8Solid !ortion:

Erythrocytes V +ed 4lood Cells %+4C& %no (*&

o Contain ?emoglo!in which transports )Gfrom lungs to cells

and C)Gfrom cells to lungs

.eu=ocytes V 0hite 4lood Cells %04C&

o Primary cells of the immune systemthey produce

anti!odies

Throm!ocytes V Platelets %no nuclei&


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o Start the clotting process !y initiating the production of!rin

o If clotted material is removed3 left with yellow li5uid V

serumo 4lood Type:

ntigens are found on +4Cs and nti!odies are produced !y 04Cs

4lood Type ntigens on +4Cnti!odies inSerum

(onor For +ecipient For

4 3 4 3 )

4 4 43 4 43 )

4 and 4 *one 4 ll

) *one and 4 ll )

+h ( 8888

+h 8 8888 (

Universal (onor: )8 Universal cceptor: 44lood has 1LL su! types to further identify victim or perpetrator

Screening Tests: IS IT 4.))(o ll use an o$idiHa!le colorless chemical an o$idiHing agent that is

catalyHed !y 6heme7 %hemoglo!in& to produce a visi!le product %color orlight&

.uminol V product Duoresces when in presence of heme

Oastle82eyer test V phenolphthalein %P?T?& that turns !right pin=

?emasti$ %4enHidine test&

)rtho8tolidine test

.eucomalachte green test

Conrmatory Tests: IS IT ?U2* 4.))(

o Teichmann Crystal Test forms !rown visi!le crystals under the microscope

o Ta=ayama Crystal Test

forms pin= needle8shaped crystals under the microscope

o Precipitin Test animal !lood that has developed anti!odies against human antigens

when e$posed to human !lood will form a coagulated !and atintersection

o ?ematrace

immunological testutiliHes the anti!ody8antigen reaction

dye changes color when anti!ody8antigen coagulation occurs

IndividualiHation: (* Tests Physical properties of 4lood:

o 8 viscous li5uid that has the potential to dry//

o 8Consider all of the following when recreating a crime scene !ased on !lood

spatter: surface te$ture

direction the !lood traveled

degree of circular distortion %angle of impact&: sin81%width#length&

stain convergence lines

%point of origin V where all droplets originated from&

(* %e &or 'NA()u$an *dentit+ Teting:

o Forensic Criminal Cases

o C)DIS V Com!ined (* Inde$ System

o ,hat t+!e o& &orenic cae i 'NA $otl+ ued &or

+ape#Se$ual ssault %more than G out of cases&

Paternity Testing

?istorical Investigations

2issing Persons Investigations


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2ass (isasters

2ilitary (* %6dog tag7&

o ,hat !art o& a 'NA i ued &or &orenic !ur!oe

*)*8C)(I*- (* V Spacer (* V 6"un= (*7

Y L'1M % million !ases& is uni5ue to an individual person

Y 'M same genome fore every person

(* V (eo$yri!onucleic cid

o

6The 4lueprint for .ife7 Str!ct!re o" #NA:

o CE.. 7*UC.EUS 7C?+)2)S)2E 7-E*E 74SE PI+

o (ou!le ?eli$ structure composed of !ase pairs

o 4ase Pairs: denine8Thymine3 Cytosine8-uanine

o $enesare what 6code7 for !odily structures and functions

o %!tations are changes within the genes from one generation to the ne$t

Steps "or #NA &rocessing:

o 1' (* E$traction

o G' (* @uantication

o ' PC+ mplication

o J' nalysis

T'o %et(ods o" &rocessing #NA:

o 1' +estriction Fragment .ength Polymorphism %+F.P&

o G' Polymerase Chain +eaction %PC+& Short Tandem +epeat %ST+&

Restriction Fragment Lengt( &olymorp(ism )RFL&*:o .arger sample siHe necessary %dime85uarter siHed drop#stain&

o Uses gel electrophoresis

o Restriction en+%mes%6chemical scissors7& cut the (* at specic

recognition sites' This 6cutting7 process generates #i,erent si+e# pieces o DN('

o The (* fragments are placed in an electrop"oresis geland a charge isapplied % at one end andat the other end&'

o The di;erent siHed ragments migrate towards the end of the gel'

o The smaller pieces move the fastest and farthest'

o The #i,erent si+e# ragments pro#uce ban#s along t"e gel'

o To visualiHe the !ands3 $8ray lm is used'

&CR + S(ort tandem repeats )STR*

o PC+: ma=es many copies of a segment of (* %(* amplication&

o S"ort Tan#em Repeats -STR. Ho' it 'or,s:+estriction enHymes recogniHe a speci/c repeating

patternand cuts the (* fragment at the !eginning and end' Thisgenerates di;erentsiHed fragments' -el electrophoresis or capillar% electrop"oresis isthen run to separate the di;erent fragments'

*itoc"on#rial DN( -mtDN(. (nal%sis:o mt(* comes from *ot"er

o I we cannot obtain nuclear DN( -nDN(. it can be use# or

o i#enti/cation purposes

Unit R: Forensic To$icology

To$icology: Endogenous Su!stance: *aturally )ccurring in the 4ody'

E$ogenous Su!stance: Foreign su!stance %drug or to$in& in the !ody

To$in: ny material e$erting a life8threatening e;ect upon a living organism'

to$ic response re5uires:

o E$posure

o (ose

o 2echanism %how it interferes with !odily functions&

To$icology: The science of adverse e;ects of chemicals on living organisms'


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To$ic e;ect depends on (epend on:

o ge

o 0eight

o ?ealth

o (ose

To$ic e;ect can !e:

o ?emolytic: ttac=ing the circulatory system and muscle tissue

o

*euroto$ic: ttac=ing the central nervous system %C*S& causes heart failureand !reathing dis surface where neurotransmitters inducetheir normal e;ects'

gonist: The drug or poison mimics the action of the transmitter'

ntagonist: The drug or poison !inds to a receptor and !loc=s the transmitter'

+outes of entry:

o )rally Ta!lets3 capsules3 li5uids

o +ectally

Suppositories

o Intravenously In"ected in li5uid form through a needle

o Inhaled through lungs

-ases3 vapors3 or particles

o !sorption through s=in Patches on s=in

o !sorption through mucous mem!ranes

Snorting3 sni


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(rugs:

(epressants

o lcohol3 !ar!iturates3 tran5uiliHers3 inhalants3 -?43 rohypnol

?allucinogens

o T?C3 .S(3 PCP3 2escaline3 Psilocy!in3 Oetamine

Stimulants

o Cocaine3 mphetamines3 2eth3 Ca;eine

*arcotics %)piates3 )pioids&o 2orphine3 Codeine3 ?eroin3 (arvon3 2ethadone

Steroids

o Corticosteroids3 na!olic Steroids

ntidepressants

o Tricyclics3 2)I>s3 SS+I>s

Unit X: 4allistics

Unit W: Serial Oillers

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