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

Calvin Goddard: developed the comparison microscope for bullet comparisons.

1813 1879

1892 1929

…more History1910

Principles of document examination

1950’s

Microscopy as a tool for the forensic scientist

1893

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.

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

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.

Coppolino Case Study

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

Dr. Karow

Carmela’s remains

Carmela Coppolino

Circa 1966Mary Gibson (Mary Coppolino – second wife)

Marjorie Farber, widow of William Farber, mistress of Carl Coppolino

Dr. Carl Coppolino

Spring Chicken Gibson

July 30, 1963William 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.