The document discusses forensic science and evidence analysis. It begins with an activity for students to list types of forensic evidence. It then discusses Locard's exchange principle which states that criminals leave evidence behind and take evidence with them during crimes. The document outlines the goals of forensic science to determine the provenance or origin of evidence and link it to people, places, or things. It describes the different departments in a crime lab and types of analyses performed. The roles of forensic scientists and expert witnesses are also summarized.

1. Do Now
 Withyour partner list as many
types of forensic evidence as you
can
 Think of all those CSI’s and L&O’s
you’ve watched!
 Team with longest list gets bonus
points!

2. Forensic Science
An Introduction

3. What is forensic science?
 Science in service to the law
 “…the application of science to
those criminal and civil laws that
are enforced by police agencies in
the criminal justice system.”
Saferstein

4. What’s the key concept in FS?
 Locard’s Exchange Principle
(~1910)
 Whenever a criminal comes in
contact with a person or object
there is a cross-transfer of
evidence.

5. What are the consequences of
Locard’s Exchange Principle?
 The perpetrator leaves
evidence behind and also
takes evidence away
 The longer you wait
before collecting evidence
the less there is left
 Every person at the crime
scene including police
investigators will
contaminate it

6. Realistic?

7. What is Forensic Science Trying to
Do?
 The goal of Forensic Chemistry is to
determine the provenance of a sample.
 Link it to a person, place or thing
prov·e·nance
Pronunciation: 'präv-n&n(t)s, 'prä-v&-"nän(t)s
Function: noun
Etymology: French, from provenir to come forth, originate, from Latin
provenire, from pro- forth + venire to come -- more at PRO-, COME
1 : ORIGIN, SOURCE
2 : the history of ownership of a valued object or work of art or literature

8. The Crime Lab
Physical
Science
Firearms Biology
Photography Documents
Pathologist
Crime
Odontologist
Lab
Voiceprint
Polygraph
Analysis
Latent
Toxicology Evidence
Engineer Fingerprints Psychiatrist
Collection
Anthropologist Entomologist

9. Activity Time!
 Assign each of the items in your evidence
list to the proper department in the crime
lab
 Feel free to add more types of evidence
 Populate your crime lab with your favorite
TV characters

10. Anthrax Letters
5 dead
17 sickened
What types of evidence would you look for?

11. Anthrax Letters
 Trace hair and fibers in envelope
 Ink analysis may reveal manufacturer
 DNA from stamp or envelope seal
 Cellophane tape ends match over four letters
 Paper examination may identify manufacturer
 Fingerprints
 Photocopier toner may reveal manufacturer
 Handwriting analysis shows four letters written by same
person
 Indented writing
 Bar codes for mail handling

12. Analytic vs. Forensic Chemistry
Similarities
Analytic Forensic
 Wants to find  Wants to find
composition of composition of
samples samples
 Compounds  Compounds
 Proportions in  Proportions in
mixtures mixtures
 Uses same  Uses same
instruments as instruments as
forensic analytical

13. Analytic vs. Forensic Chemistry
Differences
Analytic Forensic
 Known source  Need to determine
 Good idea of what the source
composition is likely  Little knowledge of
to be composition
 Used for quality  Often complex
control mixtures so hard to
 Well defined samples find appropriate
and controls controls

14. Roles of the Forensic Scientist
 Analyze physical evidence
 Provide expert testimony
 Train evidence collection units in
recognition, collection and
preservation of evidence
Would you expect to see Gil Grissom
collecting evidence at a crime scene?

15. The Expert Witness
 An expert witness can testify as
to his/her opinion of what the
evidence indicates
 A lay witness can only testify as
to fact

16. The Expert Witness
 Trial judge must be satisfied that the
expert
 Has skill or knowledge that will aid the court
in determining the truth
 Education (degrees, courses)
 Training (internship under experienced
practitioner)
 Experience (years on the job, publications,
professional societies)
 Trial judge is the gatekeeper

17. The Expert Witness
 Jury assigns weight to the expert’s
opinions
 Jury looks at
 Credentials
 Demeanor
 Whether material is presented simply and
clearly
 Jury is the trier of fact

18. And Now for Some Expert
Testimony
My Cousin
Vinny
http://myafn.dodmedia.osd.mil/img/tv/criticschoice/cousinvin.jpg

19. A Big Driver in the Plot
 Can the evidence be admitted
into court?

20. Admissibility: A Moving Target
 Frye v. US (1923)
 Scientific evidence is admissible only if it has
gained general acceptance in the field
 Rejected polygraph opinions
 Historical Perspective
 Tennessee v. John Scopes (1925)
 The Monkey Trial

21. Admissibility: A Moving Target
 Coppolino v. State of Florida (1968)
 Doctor accused of poisoning his wife with
succinylcholine chloride
 New and unique tests performed specifically
for this case
 Detected by-products of metabolism of poison
(succinic acid)
 Admissible if based on scientifically valid
principles and techniques

22. Admissibility: A Moving Target
 Federal Rule of Evidence 702 (1975)
 Approved by Congress
 More flexible general relevance test for admissibility
of opinion testimony by experts
 “If scientific, technical or other specialized knowledge
will assist the trier of fact to understand the evidence
or to determine a fact at issue, a witness qualified as
an expert by knowledge, skill, experience, training, or
education, may testify thereto in the form of an
opinion or otherwise.”

23. Admissibility: A Moving Target
 Daubert v. Merrell Dow Pharmaceuticals (1993)
 When expert evidence based on “scientific
knowledge” is offered at trial, the judge acts as
gatekeeper to determine if the evidence is “reliable”
 Four suggested factors in determining reliability
 Testable using the scientific method
 Peer reviewed
 Error rates
 Acceptability to the scientific community
 Trial judge given lots of flexibility
 Muddy waters—what is scientific knowledge?
 What about other types of experts?

24. Admissibility: A Moving Target
 Why Daubert won on appeal
 When Congress passed Rule 702 it ignored
the Frye general acceptability criterion
 Frye was no longer “good law”--

25. Admissibility: A Moving Target
 Kumho Tire Co v. Carmichael (1999)
 Daubert factors are extended to non-scientist
expert witnesses.
 Daubert factors are not the only ones that can
be considered
 Trial judge now has enormous flexibility

26. And it’s not settled yet…..
 Daubert and Kumho apply to federal cases
only
 18 State Courts have adopted Daubert
standards
 Other State Courts have rejected Daubert
and still use a modified Frye standard

27. What’s driving the growth of FS?
 Miranda decision
 Fewer confessions
 Increase in drug seizures and arrests
 More testing
 DNA profiling
 More testing with sophisticated equipment
 Other new technologies

28. Miranda vs. Arizona (1966)
 Before questioning by the
police, suspects must be
informed that they have:
 The right to remain silent
 The right to consult an attorney
 If indigent an attorney will be
provided for them
 Anything they say may be used
against them in court Arizona Department of
Library Archives and Public
Records)

29. Dickerson
 Dickerson vs US (2000)
 Congress passed law in 1968 saying voluntary
confessions are exempt from Miranda
 Supreme Court overrules Congress in 2000
 Congress can’t overrule the Supreme Court on
constitutionally guaranteed rights except by
the amendment process

30. Results of Miranda
 Confessions are less likely to hold
up in court since the burden of
proof of Miranda statement lies
on police
 Police and prosecutors rely more
independent (scientific) evidence
to prove guilt

31. What is the most common task a
forensic scientist performs?
 Take 5 minutes and discuss this in groups
of 4 and then be ready to report out your
reasoning.

32. Crime Wave or Better
Enforcement?

33. Federal Drug Seizures

34. Arrests by Drug Type

36. The Economics of Drugs
 According to the United Nations Office on Drugs and
Crime, "[T]he value of the global illicit drug market for
the year 2003 was estimated at US$13 bn [billion] at the
production level, at $94 bn at the wholesale level (taking
seizures into account), and at US$322bn based on retail
prices and taking seizures and other losses into
account."
 This is larger than the total economies of 88% of the
countries in the world!
 Source: United Nations Office on Drugs and Crime
(UNODC), World Drug Report 2005 (Vienna, Austria:
UNODC, June 2005), p. 127.

37. Average % THC in Marijuana
Seizures
Recent seizures in Atlanta had plants with 18% THC content.
http://www.usdoj.gov/ndic/pubs11/18862/images/fig1.gif

38. The Forensic All Stars
 Mathieu Orfila (1787-1853)
 Father of toxicology
 Alphonse Bertillon (1853-1914)
 First system of personal identification
 Francis Galton (1822-1911)
 Classification of fingerprints
 Dr. Leon Lattes (1887-1954)
 Determination of blood groupings from dried
blood stains

39. The Forensic All Stars
 Calvin Goddard (1891-1955)
 Father of ballistics
 Use of comparison microscope
 Albert S. Osborn (1858-1946)
 Fundamental principles of document
examination
 Walter C. McCrone (1916-2002)
 Application of microscopy to analytic problems

40. The Forensic All Stars
 Hans Gross (1847-1915)
 First text detailing application of science to
criminal investigation
 Edmond Locard (1877-1966)
 Locard’s Exchange Principle
 Thereis an exchange of materials whenever two
objects come in contact

41. What is Science?
 An organized body of knowledge about
nature
 A method for exploring nature and the
order in it
 A set of tools for solving problems about
nature

42. Coast Guard Drug Seizures