Forensic chemistry introduction

Do NowDo Now

With your partner list as With your partner list as many types of forensic many types of forensic evidence as you canevidence as you can Think of all those CSI’s and Think of all those CSI’s and

L&O’s you’ve watched!L&O’s you’ve watched! Team with longest list gets Team with longest list gets

bonus points!bonus points!

Forensic ScienceForensic Science

An IntroductionAn Introduction

What is forensic science?What is forensic science?

Science in service to the lawScience in service to the law

“…“…the application of science to the application of science to those criminal and civil laws that those criminal and civil laws that are enforced by police agencies in are enforced by police agencies in the criminal justice system.”the criminal justice system.”

SafersteinSaferstein

What’s the key concept in FS?What’s the key concept in FS?

Locard’s Exchange Principle Locard’s Exchange Principle (~1910)(~1910) Whenever a criminal comes in Whenever a criminal comes in

contact with a person or object contact with a person or object there is a there is a cross-transfercross-transfer of of evidence.evidence.

What are the consequences of What are the consequences of Locard’s Exchange Principle?Locard’s Exchange Principle?

The perpetrator leaves The perpetrator leaves evidence behind and evidence behind and also takes evidence also takes evidence awayaway

The longer you wait The longer you wait before collecting before collecting evidence the less evidence the less there is leftthere is left

Every person at the Every person at the crime scene including crime scene including police investigators police investigators will contaminate itwill contaminate it

Realistic?Realistic?

What is Forensic Science Trying to What is Forensic Science Trying to Do?Do?

The goal of Forensic Chemistry is to The goal of Forensic Chemistry is to determine the determine the provenanceprovenance of a sample. of a sample. Link it to a person, place or thingLink it to a person, place or thing

prov·e·nanceprov·e·nance Pronunciation: 'präv-n&n(t)s, 'prä-v&-"nän(t)sPronunciation: 'präv-n&n(t)s, 'prä-v&-"nän(t)sFunction: Function: nounnounEtymology: French, from Etymology: French, from provenir provenir to come forth, originate, from Latin to come forth, originate, from Latin provenire, provenire, from from pro- pro- forth + forth + venire venire to come -- more at to come -- more at PRO-PRO-, , COMECOME11 : : ORIGINORIGIN, , SOURCESOURCE22 :: the history of ownership of a valued object or work of art or the history of ownership of a valued object or work of art or literature literature

http://www.m-w.com/dictionary/pro-

http://www.m-w.com/dictionary/come

http://www.m-w.com/dictionary/origin

http://www.m-w.com/dictionary/source

The Crime LabThe Crime Lab

Firearms

Photography

Voiceprint Analysis

Toxicology Evidence Collection

Latent Fingerprints

Polygraph

Documents

Biology

Physical Science

Crime Lab

Psychiatrist

Odontologist

EntomologistAnthropologist

Pathologist

Engineer

Activity Time!Activity Time!

Assign each of the items in your Assign each of the items in your evidence list to the proper evidence list to the proper department in the crime labdepartment in the crime lab

Feel free to add more types of Feel free to add more types of evidence evidence

Populate your crime lab with your Populate your crime lab with your favorite TV charactersfavorite TV characters

Anthrax LettersAnthrax Letters

What types of evidence would you look for?

5 dead17 sickened

Anthrax LettersAnthrax Letters Trace hair and fibers in envelopeTrace hair and fibers in envelope Ink analysis may reveal manufacturerInk analysis may reveal manufacturer DNA from stamp or envelope sealDNA from stamp or envelope seal Cellophane tape ends match over four lettersCellophane tape ends match over four letters Paper examination may identify manufacturerPaper examination may identify manufacturer FingerprintsFingerprints Photocopier toner may reveal manufacturerPhotocopier toner may reveal manufacturer Handwriting analysis shows four letters written by Handwriting analysis shows four letters written by

same personsame person Indented writingIndented writing Bar codes for mail handlingBar codes for mail handling

Analytic vs. Forensic ChemistryAnalytic vs. Forensic ChemistrySimilaritiesSimilarities

AnalyticAnalytic Wants to find Wants to find

composition of composition of samplessamples CompoundsCompounds Proportions in Proportions in

mixturesmixtures Uses same Uses same

instruments as instruments as forensicforensic

ForensicForensic Wants to find Wants to find

composition of composition of samplessamples CompoundsCompounds Proportions in Proportions in

mixturesmixtures Uses same Uses same

instruments as instruments as analyticalanalytical

Analytic vs. Forensic ChemistryAnalytic vs. Forensic ChemistryDifferencesDifferences

AnalyticAnalytic Known sourceKnown source Good idea of what Good idea of what

the composition is the composition is likely to belikely to be

Used for quality Used for quality controlcontrol

Well defined Well defined samples and samples and controlscontrols

ForensicForensic Need to determine Need to determine

sourcesource Little knowledge of Little knowledge of

compositioncomposition Often complex Often complex

mixtures so hard to mixtures so hard to find appropriate find appropriate controlscontrols

Roles of the Forensic ScientistRoles of the Forensic Scientist

Analyze physical evidenceAnalyze physical evidence Provide expert testimonyProvide expert testimony Train evidence collection units in Train evidence collection units in

recognition, collection and recognition, collection and preservation of evidencepreservation of evidence

Would you expect to see Gil Grissom Would you expect to see Gil Grissom collecting evidence at a crime collecting evidence at a crime scene?scene?

The Expert WitnessThe Expert Witness

An expert witness can testify An expert witness can testify as to his/her as to his/her opinionopinion of what of what the evidence indicatesthe evidence indicates

A lay witness can only testify A lay witness can only testify as to as to factfact


Trial judgeTrial judge must be satisfied that the must be satisfied that the expertexpert Has skill or knowledge that will aid the Has skill or knowledge that will aid the

court in determining the truthcourt in determining the truth Education (degrees, courses)Education (degrees, courses) Training (internship under experienced Training (internship under experienced

practitioner)practitioner) Experience (years on the job, publications, Experience (years on the job, publications,

professional societies)professional societies)

Trial judgeTrial judge is the gatekeeper is the gatekeeper


JuryJury assigns weight to the expert’s assigns weight to the expert’s opinionsopinions

JuryJury looks at looks at CredentialsCredentials DemeanorDemeanor Whether material is presented simply Whether material is presented simply

and clearlyand clearly JuryJury is the is the trier of facttrier of fact

And Now for Some Expert And Now for Some Expert TestimonyTestimony

My My Cousin Cousin VinnyVinny

http://myafn.dodmedia.osd.mil/img/tv/criticschoice/cousinvin.jpg

A Big Driver in the PlotA Big Driver in the Plot

Can the evidence be Can the evidence be admitted into court?admitted into court?

Admissibility: A Moving TargetAdmissibility: A Moving Target

Frye v. US (1923)Frye v. US (1923) Scientific evidence is admissible only if Scientific evidence is admissible only if

it has gained it has gained general acceptancegeneral acceptance in the in the fieldfield

Rejected polygraph opinionsRejected polygraph opinions Historical PerspectiveHistorical Perspective

Tennessee v. John Scopes (1925)Tennessee v. John Scopes (1925) The Monkey Trial The Monkey Trial


Coppolino v. State of Florida (1968)Coppolino v. State of Florida (1968) Doctor accused of poisoning his wife Doctor accused of poisoning his wife

with succinylcholine chloridewith succinylcholine chloride New and unique tests performed New and unique tests performed

specifically for this casespecifically for this case Detected by-products of metabolism of Detected by-products of metabolism of

poison (succinic acid)poison (succinic acid) Admissible if based on Admissible if based on scientifically valid scientifically valid

principles and techniquesprinciples and techniques


Federal Rule of Evidence 702 (1975)Federal Rule of Evidence 702 (1975) Approved by CongressApproved by Congress More flexible general relevance test for More flexible general relevance test for

admissibility of opinion testimony by expertsadmissibility of opinion testimony by experts ““If scientific, technical or other specialized If scientific, technical or other specialized

knowledge will assist the knowledge will assist the trier of facttrier of fact to to understand the evidence or to determine a fact understand the evidence or to determine a fact at issue, a witness qualified as an expert by at issue, a witness qualified as an expert by knowledgeknowledge, , skillskill, , experienceexperience, , trainingtraining, or , or educationeducation, may testify thereto in the form of an , may testify thereto in the form of an opinion or otherwise.”opinion or otherwise.”

Admissibility: A Moving TargetAdmissibility: A Moving Target Daubert v. Merrell Dow Pharmaceuticals (1993)Daubert v. Merrell Dow Pharmaceuticals (1993)

When expert evidence based on “scientific When expert evidence based on “scientific knowledge” is offered at trial, knowledge” is offered at trial, the judgethe judge acts as acts as gatekeeper to determine if the evidence is “reliable”gatekeeper to determine if the evidence is “reliable”

Four suggested factors in determining reliabilityFour suggested factors in determining reliability Testable using the scientific methodTestable using the scientific method Peer reviewedPeer reviewed Error ratesError rates Acceptability to the scientific communityAcceptability to the scientific community

Trial judge given lots of flexibilityTrial judge given lots of flexibility Muddy waters—what is scientific knowledge?Muddy waters—what is scientific knowledge?

What about other types of experts?What about other types of experts?


Why Why DaubertDaubert won on appeal won on appeal When Congress passed Rule 702 it When Congress passed Rule 702 it

ignored the ignored the FryeFrye general acceptability general acceptability criterioncriterion

FryeFrye was no longer “good law”-- was no longer “good law”--


Kumho Tire Co v. CarmichaelKumho Tire Co v. Carmichael (1999) (1999) DaubertDaubert factors are extended to factors are extended to non-non-

scientistscientist expert witnesses. expert witnesses. DaubertDaubert factors are not the only ones factors are not the only ones

that can be consideredthat can be considered Trial judge now has enormous flexibilityTrial judge now has enormous flexibility

And it’s not settled yet…..And it’s not settled yet…..

DaubertDaubert and and Kumho Kumho apply to federal apply to federal cases onlycases only

18 State Courts have adopted 18 State Courts have adopted DaubertDaubert standards standards

Other State Courts have rejected Other State Courts have rejected Daubert Daubert and still use a modifiedand still use a modified Frye Frye standardstandard

What’s driving the growth of FS?What’s driving the growth of FS?

Miranda decisionMiranda decision Fewer confessionsFewer confessions

Increase in drug seizures and arrestsIncrease in drug seizures and arrests More testingMore testing

DNA profilingDNA profiling More testing with sophisticated More testing with sophisticated

equipmentequipment Other new technologiesOther new technologies

Miranda vs. Arizona (1966)Miranda vs. Arizona (1966)

Before questioning by the Before questioning by the police, police, suspectssuspects must be must be informed that they have:informed that they have: The right to remain silentThe right to remain silent The right to consult an The right to consult an

attorneyattorney If indigent an attorney will If indigent an attorney will

be provided for thembe provided for them Anything they say may be Anything they say may be

used against them in courtused against them in courtArizona Department of Library Archives and Public Records)

DickersonDickerson

Dickerson vs US (2000)Dickerson vs US (2000) Congress passed law in 1968 saying Congress passed law in 1968 saying

voluntary confessionsvoluntary confessions are exempt from are exempt from MirandaMiranda

Supreme Court overrules Congress in Supreme Court overrules Congress in 20002000

Congress can’t overrule the Supreme Congress can’t overrule the Supreme Court on constitutionally guaranteed Court on constitutionally guaranteed rights except by the amendment rights except by the amendment processprocess

Results of MirandaResults of Miranda

Confessions are less likely to Confessions are less likely to hold up in court since the hold up in court since the burden of proof of Miranda burden of proof of Miranda statement lies on policestatement lies on police

Police and prosecutors rely Police and prosecutors rely more independent (scientific) more independent (scientific) evidence to prove guiltevidence to prove guilt

What is the most common task a What is the most common task a forensic scientist performs?forensic scientist performs?

Take 5 minutes and discuss this in Take 5 minutes and discuss this in groups of 4 and then be ready to groups of 4 and then be ready to report out your reasoning.report out your reasoning.

Crime Wave or Better Crime Wave or Better Enforcement?Enforcement?

Federal Drug SeizuresFederal Drug Seizures

Arrests by Drug TypeArrests by Drug Type

The Economics of DrugsThe Economics of Drugs According to the United Nations Office on Drugs According to the United Nations Office on Drugs

and Crime, "[T]he value of the global illicit drug and Crime, "[T]he value of the global illicit drug market for the year 2003 was estimated at market for the year 2003 was estimated at US$13 US$13 bnbn [billion] at the production level, at [billion] at the production level, at $94 bn$94 bn at at the wholesale level (taking seizures into account), the wholesale level (taking seizures into account), and at and at US$322bnUS$322bn based on retail prices and based on retail prices and taking seizures and other losses into account." taking seizures and other losses into account."

This is larger than the total economies of 88% of This is larger than the total economies of 88% of the countries in the world!the countries in the world!

Source: United Nations Office on Drugs and Crime Source: United Nations Office on Drugs and Crime (UNODC), World Drug Report 2005 (Vienna, (UNODC), World Drug Report 2005 (Vienna, Austria: UNODC, June 2005), p. 127.Austria: UNODC, June 2005), p. 127.

Average % THC in Marijuana Average % THC in Marijuana SeizuresSeizures

http://www.usdoj.gov/ndic/pubs11/18862/images/fig1.gif

Recent seizures in Atlanta had plants with 18% THC content.

The Forensic All StarsThe Forensic All Stars

Mathieu Orfila (1787-1853)Mathieu Orfila (1787-1853) Father of toxicologyFather of toxicology

Alphonse Bertillon (1853-1914)Alphonse Bertillon (1853-1914) First system of personal identificationFirst system of personal identification

Francis Galton (1822-1911)Francis Galton (1822-1911) Classification of fingerprintsClassification of fingerprints

Dr. Leon Lattes (1887-1954)Dr. Leon Lattes (1887-1954) Determination of blood groupings from Determination of blood groupings from

dried blood stainsdried blood stains


Calvin Goddard (1891-1955)Calvin Goddard (1891-1955) Father of ballisticsFather of ballistics Use of comparison microscopeUse of comparison microscope

Albert S. Osborn (1858-1946)Albert S. Osborn (1858-1946) Fundamental principles of document Fundamental principles of document

examinationexamination Walter C. McCrone (1916-2002)Walter C. McCrone (1916-2002)

Application of microscopy to analytic Application of microscopy to analytic problemsproblems


Hans Gross (1847-1915)Hans Gross (1847-1915) First text detailing application of science First text detailing application of science

to criminal investigationto criminal investigation Edmond Locard (1877-1966)Edmond Locard (1877-1966)

Locard’s Exchange PrincipleLocard’s Exchange Principle There is an exchange of materials whenever There is an exchange of materials whenever

two objects come in contacttwo objects come in contact

What is Science?What is Science?

An organized An organized body of knowledgebody of knowledge about natureabout nature

A A methodmethod for exploring nature and for exploring nature and the order in itthe order in it

A set of A set of toolstools for solving problems for solving problems about natureabout nature

Coast Guard Drug SeizuresCoast Guard Drug Seizures

Technology

Forensic chemistry introduction