Transcript Introduction to Forensic Science

Introduction to
Forensic Science
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What does “forensic science” mean?
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The presentation of science or scientific
evidence in a public forum (court of law)
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Dates back to China, 1248
Sherlock Holmes
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Fictional character developed by author
Sir Arthur Conan Doyle.
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First to apply serology, fingerprinting,
firearm identification, and questioneddocument examination
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All of this - from fiction - before accepted
by real-life criminal investigations.
Mathieu Orfila - 1813
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Father of Toxicology
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Lafarge Trial (Marie) - arsenic
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Book: Traite des poisons or Toxicologie
general - first scientific study of the
detection and pathological effects of
poisons - established toxicology as a
distinct field of forensic science.
Alphonse Bertillon - 1879
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The father of criminal identification
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Developed anthropometry - using body
length measurements as unique properties
- took 243 separate measurements
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Method was coined “Bertillonage”
Francis Galton
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Fingerprinting
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Developed methodology for identification
using the friction ridges on fingers
Basics still used today
His work has been enhanced by Sir Edward
Henry - father of modern fingerprinting
Henry developed a filing method for storing
fingerprint patterns/records prior to computer
storage capabilities
Leone Lattes - 1915
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Blood testing - used technique developed
by Dr. Karl Landsteiner
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Bloodstains - developed method to
determine blood type from dried blood
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Discovered that blood typing could be
used as a means of identification
Calvin Goddard - 1920s
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Individualization of weapons
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Firing pin marks on shell casings
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Refined the technique of bullet
comparisons with the gun from which it
was fired
Albert S. Osborn
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Handwriting expert - established the
fundamental principles of document
examination.
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Challenged the notion of “told” rather than
“shown”
Hans Gross
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First real life “scientific detective” described the application of scientific
disciplines to the field of criminal
investigation
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Austrian lawyer
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Coined the term “Criminalistics”
Hans Gross
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Wrote about: forensic medicine toxicology,
serology, ballistics, and anthropometry
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Suggested using: mineralogists, ecologist,
and botanists
J. Edgar Hoover
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Reorganized the Bureau of Investigations
in 1924
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Included fingerprint cards
1932 now FBI
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Organized a national laboratory that aimed to
offer forensic services of all law enforcement
agencies
Edmond Locard
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Locard’s Exchange Principle - whenever
two objects come in contact, material will
be exchanged between them.
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Every criminal can be tied to crime by dust
particles carried from the scene
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Ex: counterfeit coins - metal found that
matched those of the coins found on 3
suspects clothes - confronted with evidence they confessed
Evidence: What is it?
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Direct: evidence in the form of a statement
made under oath - also known as
testimonial evidence.
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Physical evidence: any object or material
that is relevant in a crime.
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Locard’s Principle
Class vs. Individual Evidence
What is it good for?
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Physical evidence
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Prove crime has been committed
Corroborate testimony
Link suspect to victim or crime scene
Establish identity of persons associated with
crime
All reconstruction of crime
Class Evidence
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Consistent with a particular source
The more class evidence that fits the
criminal - the better
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Hair
Fibers
Soil
Glass fragments
Individual
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Individualized to a single, specific source
No doubt as to what the source is
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Fingerprints
DNA
Handwriting
Voiceprints
Always involves a comparison - an
exemplar
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Piece of evidence taken from known source
Rules of Evidence
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Admissible evidence must be
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Relevant - must prove something (probative)
and address the issue of the particular crime
(material)
Reliable
Presenter must be credible and competent
Scientific Evidence
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Frye Standard
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Interpretation of evidence must be given by
an expert witness & have gained “general
acceptance” in that particular field of study
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Frey vs. U.S., 1923: court must decide if the
handling of evidence are “generally accepted”
by a meaningful segment of the relevant
scientific community
Scientific Evidence
Daubert Ruling
Daubert vs. Merrill Dow Pharmaceuticals
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Applies to federal courts & some states
Judge determines admissibility
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Guidelines for Judge
1.
2.
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Scientific theory or technique must be testable.
Must be subject to peer review and publication
Rate of error must be stated
Technique must follow standards
Consideration as to whether there is widespread
acceptance in scientific community
Common Acronyms in
Forensic Science
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AAFS-American Academy of Forensic Science
DNA - Deoxyribonucleic Acid
RNA - Ribonucleic Acid
CODIS - Combined DNA Index System
AFIS-Automated Fingerprint Identification
System
IBIS - Integrated Ballistics Identification
FBI-Federal Bureau of Investigation
More Acronyms
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DEA - Drug Enforcement Administration
ATF - (Bureau of)Alcohol, Tobacco, &
Firearms
USPS - United States Postal Service
USF&W - United States Fish &
Wildlife(Service)
PCR - Polymerase Chain Reaction (DNA)
RFLP - Restriction Fragment Length
Polymorphism
STR - Single Tandem Repeats (DNA)
More Acronyms
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SSA - Social Security Administration
IRS -Internal Revenue Service
BSPA - Bloodstain Pattern Analysis
DOA - Dead On Arrival
DUI - Driving Under the Influence
TOD - Time Of Death
PMI - Post Mortem Interval
DRT - Dead Right There
B&E - Breaking & Entering