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!
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
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
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.
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