Forensics - Northern Highlands Regional HS / Overview · – Victim was inside the car means fibers...
Transcript of Forensics - Northern Highlands Regional HS / Overview · – Victim was inside the car means fibers...
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
Mathieu Orfila: Father of Forensic toxicology
Alphonse Bertillon: developed the science of anthropometry
Francis Galton: first study of fingerprints
(Nephew of Darwin)
Calvin Goddard: developed the comparison microscope for bullet comparisons.
1813 1879
1892 1929
…more History 1910
Albert Osborne:
Principles of document examination
1950’s
Microscope as a tool for the forensic scientist
1893
Hans Gross:
Developed the application of scientific principles to criminal investigations
1910
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
August 28, 1965 Family physician, Karow, called to Coppolino home
Dr. Karow
Carmela’s remains
Carmela Coppolino
Circa 1966 Mary Gibson (Mary Coppolino – second wife)
Marjorie Farber, widow of William Farber, mistress of Carl Coppolino
Dr. Carl Coppolino
Spring Chicken Gibson
July 30, 1963 William Farber died
Mary Gibson (Mary Coppolino – second wife)
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 vs. Time in Stomach Light - 1-2 hours Medium - 3-4 hours Heavy - 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