Transcript What is Forensic Science?

What is Forensic Science?
Mark Pollitt
Associate Professor
What it ISN’T!
©2005 DEPS, Inc.
What is Science?
“There are no forbidden questions in science, no matters too sensitive or
delicate to be probed, no sacred truths. That openness to new ideas,
combined with the most rigorous, skeptical scrutiny of all ideas, sifts the wheat
from the chaff. It makes no difference how smart, august, or beloved you are.
You must prove your case in the face of determined expert criticism.”
-Carl Sagan
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What is Science?
• Organized study of natural phenomena
• Application of the scientific method
– Hypothesis
– Experiment
– Conclusions based on demonstrable proof
– Skepticism – search for alternative explanations
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Skepticism
“The tenets of skepticism do not require an advanced degree to master as
most successful used car buyers demonstrate.” The whole idea of a
democratic application of skepticism is that everyone should have the
essential tools to effectively and constructively evaluate claims of
knowledge. All science asks is to employ the same levels of skepticism we
use in buying a used car.” – Carl Sagan
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What is Forensic Science?
• Forensis – Latin meaning public, forum,
discussion
• Forensic – belonging to, suitable for use in
courts or public for a
• Forensic Science – any science used for the
purpose of law
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How is it different than “regular”
science?
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Theory
Scientific fact
Applied to
Physical evidence
So it is “applied” science!
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Physical Evidence
This is evidence that does not forget.
It is not confused by the excitement of the moment.
It is not absent because human witnesses are.
It is factual evidence.
Physical evidence cannot be wrong; it cannot perjure itself;
It cannot be wholly absent.
Only its interpretation can err. Only human failure to find it,
Study and understand it, can diminish its value.”
Paul L. Kirk, PhD
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The Three Elements
Science
Evidence
Law
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Classifications of Forensic Science
• Criminalistics: application of the principles of natural
science to the identification, evaluation, and
individualization of physical evidence which is
collected at the scene of a crime or suspicious
incident.
• Applied Science: The applied forensic sciences also
study evidence but within discipline-specific forensic
contexts.
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Examples
• Criminalistics:
– DNA
– Trace
– Questioned
Documents
– Firearms
– Drugs
– Friction Ridge
“Evidence focused”
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Examples
• Applied Sciences:
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Forensic Pathology
Forensic Odontology
Forensic Anthropology
Forensic Toxicology
Forensic Entomology
Engineering
Forensic Psychiatry
“Discipline focused”
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What Makes you a Forensic
Scientist?
• Training/education
• Standards
– ASCLD-LAB
– ISO 17025
• Environment
– Quality Management
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Policies
SOP’s
Notes
Reports
Peer review, Audits,
Inspections
– Expert testimony
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Forensic Science Paradigm
• Inman &Rudin
– Principles
• Divisible Matter
• Transfer
– Processes
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Identification
Classification/individualization
Association
Reconstruction
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Locard’s Exchange Theory of Transference
• Pioneer French criminalist – 1877-1966
• Recognized and documented that:
– When two objects come into contact, there is an
exchange of material
• Leads to the notion that a suspect cannot
enter a space without leaving trace evidence.
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“There is literally no end to the number of disciplines
That become ‘forensic’ by definition. Nor is there an
end in sight to the number of present or future specialties
That may become forensic.”
Anthony Longhetti,
Past President, AAFS-1983
©2005 DEPS, Inc.