Forensics
Forensic Science: A Definition
• Application of science to law
• Applies the knowledge and technology of
science for the definition and enforcement
of such laws.
Forensic science is the application of science to
those criminal and civil laws that are enforced
by police agencies in a criminal justice system.
History and Development
1813
Mathieu Orfila:
Father of Forensic
toxicology
1892
Francis Galton:
first study of
fingerprints
(Nephew of Darwin)
1879
Alphonse Bertillon:
developed the
science of
anthropometry
1929
Calvin Goddard:
developed the
comparison
microscope for
bullet
comparisons.
…more History
1910
Albert Osborne:
Principles of
document
examination
1893
1950’s
Microscope as a
tool for the
forensic scientist
1910
Hans Gross:
Developed the
application of
scientific
principles to
criminal
investigations
Locard’s Exchange
Principle
Locard’s Principle
"Wherever he steps, whatever he touches, whatever he
leaves, even unconsciously, will serve as a silent witness
against him. Not only his fingerprints or his footprints, but
his hair, the fibers from his clothes, the glass he breaks, the
tool mark he leaves, the paint he scratches, the blood or
semen he deposits or collects. All of these and more, bear
mute witness against him. 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 human failure
to find it, study and understand it, can diminish its value.“
Organization of the Crime Lab
• Over 320 public crime labs in the U.S…a
tripling of the number since 1966.
• Supreme Court decision Miranda v.
Arizona (1966)
• Increase in drug abuse
• Advent of DNA profiling
• Most State Governments maintain crime
labs plus satellite labs.
Services of the Crime Lab
•
•
•
•
Physical Science Unit
Biology Unit
Firearms Unit
Document Examination
Unit
• Photography Unit
•
•
•
•
•
Toxicology Unit
Latent Fingerprint Unit
Polygraph Unit
Voiceprint Analysis unit
Evidence Collection Unit
Physical Science Unit
Physical Science Unit
• Investigators:
• Chemists
• Physicists
• Geologists
• Items Identified:
• drugs, glass, paint, explosives and soil
• Job:
• Analytical and chemical analysis
Biology Unit
Biology Unit
• Investigators:
• Biologists
• Biochemists
• Identify and Compare:
• botanical materials such as wood and plants.
• Job:
• Identification and DNA profiling of dried blood
stains, other body fluids, comparison of hairs and
fibers
Firearms Unit
Firearms Unit
• Identify and examine:
•
•
•
•
Firearms
Discharged bullets
Cartridge cases
Shotgun shells
• Responsibility:
• Examination of garments to detect firearm
discharge residue
• Determine approximate distance from target when
weapon was fired.
Document Analysis Unit
Document Analysis Unit
• Identify and Examine:
• Handwriting and typewriting to determine
authenticity and/or source
• Job:
• Analysis of paper and ink and indented writings
(impressions)
• Recreate:
• Obliterations, erasures
• Burned or charred documents
Photography Unit
Photography Unit
• Examine and Record:
• Physical evidence at the scene
• Specialize in:
• Digital imaging, IR, UV, and X ray photography to
make invisible information visible to the naked eye
• Beyond the Scene:
• Preparation of photographic exhibits for courtroom
presentation.
Can you find the Relationship?
Toxicology Unit
• Investigators:
• Chemists
• Biologists
• Examine:
• Body fluids and organs for the presence or
absence of drugs and poisons.
• Determines Blood alcohol content
• Job:
• Works with the coroner or medical examiner’s
office
Latent Fingerprint Unit
Latent Fingerprint Unit
• Process and examine:
• Fingerprints to determine possible matches with
victims and suspects
Polygraph Unit
Polygraph Unit
• Job:
• Analyze respiration, perspiration, blood pressure
and pulse rate to determine credibility
• Used in conjunction with interrogation to
determine credibility of suspects and
witnesses.
Voiceprint Unit
Voiceprint Unit
• Interpret:
• Telephone threats
• Analyze:
• Tape recorded messages
• Compare:
• Suspect voice recording to evidence to match
source
Evidence Collection Unit
Evidence Collection Unit
• CSI:
• Crime Scene Investigation
• Consists of:
• trained personnel who are dispatched to the crime
scene to collect and preserve physical evidence.
• They simply collect the evidence, they do
not do every single job as seen on fiction
television.
Locard’s Principle Revisited
• Attempt the Hypothetical Case with a partner.
• Answers:
– Victim was inside the car means fibers from its interior have been
transferred onto the victim’s clothing.
– Blood from the victim has been transferred onto the velour interior.
– Fiber, blood, hair, and skin cells may also have been transferred between
the criminal and victim.
– Tire tracks from the car may have been left in the woods.
– This would probably lead to the make of car, since the tires are special.
– If the vehicle was located, small driving imperfections in the tread could
link it to the crime.
– The type of soil at the crime scene may still be on the car’s tires, too.
– Interior of suspect’s car could be tested for the fibers, hair, skin cells and
blood of the victim.
Functions of the Forensic Scientist
• Frye v. United States: 1923 Rejection of Lie Detector
(Polygraph) results necessitated guidelines for
determining judicial admissibility of scientific
examinations.
• The Frye Standard: The court must decide if the
questioned procedure, technique or principles are
“generally accepted” by a meaningful segment of the
scientific community.
Daubert v. Merrel
• Whether the scientific technique or theory
can be tested.
• Whether the technique or theory has been
subject to peer review and publication.
• The technique’s potential for error.
• Existence and maintenance of standards
controlling the technique’s operation.
• Whether the scientific theory or method has
attracted widespread acceptance within a
relevant scientific community.
Types of Law – The Three Cs
• Criminal
• Civil
• Common
Note: there are others but these will be the primary ones in
many of our cases
• Probable Cause: situation in which a reasonable and
prudent person, viewing the available informatio,n would
conclude that a crime has been committed and that the
suspect committed it
Coppolino Case Study
Dr. Karow
August 28, 1965
Family physician,
Karow, called to
Coppolino home
Carmela Coppolino
Carmela’s remains
Circa 1966
Mary Gibson
(Mary Coppolino
– second wife)
Marjorie Farber,
widow of William
Farber, mistress of
Carl Coppolino
Dr. Carl Coppolino
Spring Chicken Gibson
Mary Gibson
(Mary Coppolino
– second wife)
July 30, 1963
William Farber died
Carl and his
lawyer
Carl in
custody
Coppolino v. State
• M.E. testified that victim died of an overdose of a drug
called succinylcholine chloride based on his toxicology
report.
• Succinylcholine chloride breaks down into succinic acid
in the body.
• This drug had never before been detected in a human
body.
• Defense argued that this test was new and absence of
corroborative experimental data by other scientists.
• The court rejected the defense’s argument on the
grounds that although the tests may be new and unique,
they are admissible only if they are based on
scientifically valid principles and techniques.
Expert Testimony
• Must be competent: education degrees, member of
applicable societies, published papers or books, etc.
• Defense may cross-examine the
potential expert witness.
• The individual trial judge is the
ultimate decision maker
regarding expert witnesses.
Training in Recognition, Collection,
and Preservation of Evidence
• Specially trained evidence collectors: CSI
• On 24-hour call to aid criminal
investigators in retrieving evidence
• Specially equipped with all the proper
evidence collection equipment
• Unfortunately, some police forces still
don’t use them or the police themselves
have contaminated the crime scene before
the CSI team gets there!
Forensic Pathology
• Investigation of sudden, unnatural, unexplained, or
violent death.
• Medical Examiner vs Coroner = M.D. vs political
appointee.
• Autopsy: http://www.pathguy.com/autopsy.htm
• Causes of death: natural, homicide, suicide, accident,
undetermined.
• Rigor mortis: starts within the first 24 hours and
disappears after 36 hours. Helpful in estimating time of
death. See “Algor mortis”
• Livor mortis: settling of blood after the heart stops. Skin
appears dark blue. Used to determine position of body
at time of death.
Rigor Mortis
• Chemical change in the muscles after death,
causing the limbs of the corpse to become stiff
and difficult to move or manipulate.
• 3-12 hours; disappears after 72 hours in
humans.
Muscles and Rigor Mortis
Rigor Mortis
Livor Mortis
Livor Mortis
Determining time of Death
• Algor mortis: continual cooling of body
temperature after death
• Factors: location of body, size of body, victim’s
clothing, ambient temperature
• General Rule: Beginning about an hour after
death, the body will lose heat at a rate of 1 to 1.5
degrees F. per hour until the body reaches the
environmental temperature.
• Potassium levels in the vitreous humor of the
eye
More Time of Death Factors
• Food in victim’s stomach can establish last
time victim ate.
• Liver temperature
– Only if done at crime scene
• Anal Temperature
– Compared to ambient temperature
Stomach Contents
• Stomach begins to empty within 10
minutes of meal
Size of Meal
Light
Medium
Heavy
vs.
-
Time in Stomach
1-2 hours
3-4 hours
4-6 hours
Other Areas involving Forensics
• Anthropology: Examination of human skeletal
remains
• Entomology: insect life span can be used to
determine the time of death.
• Psychiatry: competency of suspect; serial killed
profiles
• Odontology: body identification based on dental
records; evidence using bite marks left on
victims
• Engineering: accident reconstruction to
determine causes