Forensics

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Forensics
Chapter 1 Introduction
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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.
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History and Development
1813
1879
Mathieu Orfila Father of Forensic toxicology
Alphonse Bertillon developed the science of
anthropometry
1929
1892
Calvin Goddard developed the comparison
microscope for bullet comparisons.
Francis Galton first study of fingerprints
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more History
1910
1950s
Principles of document examination
Microscopy as a tool for the forensic scientist
1893
1910
Developed the application of scientific
principles to criminal investigations
Locards Exchange Principle
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Locards 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.

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Organization of the Crime Lab

• Over 320 public crime labs in the U.Sa 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.

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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

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Physical Science Unit
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Physical Science Unit

• Investigators
• Chemists
• Physicists
• Geologists
• Items Identified
• drugs, glass, paint, explosives and soil
• Job
• Analytical and chemical analysis

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Biology Unit
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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

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Firearms Unit
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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.

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Document Analysis Unit
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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

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Photography Unit
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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.

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Can you find the Relationship?
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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 examiners
  office

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Latent Fingerprint Unit
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Latent Fingerprint Unit

• Process and examine
• Fingerprints to determine possible matches with
  victims and suspects

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Polygraph Unit
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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.

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Voiceprint Unit
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Voiceprint Unit

• Interpret
• Telephone threats
• Analyze
• Tape recorded messages
• Compare
• Suspect voice recording to evidence to match
  source

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Evidence Collection Unit
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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.

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Locards 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 victims
  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 cars tires, too.
• Interior of suspects car could be tested for the
  fibers, hair, skin cells and blood of the victim.

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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

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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.

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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 techniques potential for error.
• Existence and maintenance of standards
  controlling the techniques operation.
• Whether the scientific theory or method has
  attracted widespread acceptance within a relevant
  scientific community.

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Coppolino Case Study
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Dr. Karow

• August 28, 1965
• Family physician, Karow, called to Coppolino home

Carmelas remains
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• Circa 1966

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Dr. Carl Coppolino
Spring Chicken Gibson
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• July 30, 1963
• William Farber died

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Carl and his lawyer
Carl in custody
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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 defenses 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.

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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.

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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 dont use
  them or the police themselves have contaminated
  the crime scene before the CSI team gets there!

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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.

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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.

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Muscles and Rigor Mortis
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Rigor Mortis
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Livor Mortis
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Livor Mortis
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Determining time of Death

• Algor mortis continual cooling of body
  temperature after death
• Factors location of body, size of body,
  victims 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

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More Time of Death Factors

• Food in victims stomach can establish last time
  victim ate.
• Liver temperature
• Only if done at crime scene
• Anal Temperature
• Compared to ambient temperature

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Stomach Contents

• Stomach begins to empty within 10 minutes of meal
• Size of Meal vs. Time in Stomach
• Light - 1-2 hours
• Medium - 3-4 hours
• Heavy - 4-6 hours

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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