Introduction to Forensic Science & to the Law

Chapter 1

Forensic Science

It is the study and application of science to matters of law (criminal and civil)

Includes the business of providing timely, accurate, and thorough information to all levels of decision makers in our criminal justice system

Also called criminalistics

Criminalists vs Criminologists

A criminalist examines physical evidence for legal purposes

Criminologists study the crime scene for motive, traits, and behavior as to help interpret the evidence– They learn to think like criminals

Forensic Scientists

Applies the principles and techniques of the physical and natural sciences to the analysis of the many types of evidence that may be recovered during a criminal investigation

May also provide expert court testimony– Known as an expert witness

Individual whom the court determines possesses knowledge relevant to the trial

Developments in Forensic Science

700s AD- Chinese used fingerprints to establish identity of documents and clay sculptures

~1000- Roman courts determined that bloody palm prints were used to frame a man in his brother’s murder

1149- King Richard of England introduced the idea of the coroner to investigate questionable death

1200s- A murder in China is solved when flies were attracted to invisible blood residue on a sword of a man in the community

1598- Fidelus was first to practice forensic medicine in Italy

Developments in Forensic Science

1670- Anton van Leeuwenhoek constructed the first high powered microscope

1776- Paul Revere identified the body of General Joseph Warren based on the false teeth he had made for him

1784- John Toms convicted of murder on basis of torn edge of wad of paper in pistol matching a piece of paper in his pocket

1859- Gustav Kirchoff and Robert Bunsen developed the science of spectroscopy

1864- Crime scene photography developed

Developments in Forensic Science

1879- Alphonse Bertillion developed a system to identify people using particular body measurements

1896- Edward Henry developed the first classification system for fingerprint identification

1900- Karl Landsteiner identified human blood groups 1904- Edmond Locard formulated his famous principle,

“Every contact leaves a trace” 1922- Francis Aston developed the mass spectrometer

Developments in Forensic Science

1959- James Watson and Francis Crick discover the DNA double helix

1977- AFIS developed by FBI, fully automated in 1996

1984- Jeffrey’s developed and used the first DNA tests to be applied to a criminal case

People of Historical Significance

Mathieu Orfila- father of forensic toxicology Alphonse Bertillion- devised first scientific system of

personal identification Francis Galton- conducted first definitive study of

fingerprints and their classification Leone Lattes- developed a procedure to determine

blood type from dried bloodstains Calvin Goddard- used a comparison microscope to

determine if a particular gun fired a bullet

People of Historical Significance

Albert Osborn- developed the fundamental principles of document examination

Walter McCrone- utilized microscopy to examine evidence

Hans Gross- wrote treatise on criminal investigation Edmond Locard- considered the father of criminalistics;

responsible for Locard’s exchange principle– States that when a criminal comes in contact with an object or

a person, a cross transfer of evidence occurs

The Crime Lab

Characterized by rapid growth due to– Supreme Court decisions in the 1960s placing

greater emphasis on scientifically evaluated evidence

– Accelerated drug abuse– Initiation of DNA profiling

350 public crime labs exist at federal, state, county, and municipal levels

The Crime Lab

History– First established in 1910 by Locard– First police crime lab established in 1923 in Los

Angeles, CA– Scientific Crime Detection Lab established in 1929– First FBI crime lab opened in 1932

Crime Lab Services

5 exist– Physical science– Biology– Firearms– Document– Photographic

Physical Science Unit

Incorporates the principles of chemistry, physics, and geology to identify and compare physical evidence

Biology Unit

Applies the knowledge of biological sciences in order to investigate blood samples, body fluids, hair, and fiber samples

Firearms Unit

Investigates discharged bullets, cartridge cases, shotgun shells, and ammunition

Document Unit

Provides the skills needed for handwriting analysis and other questioned document issues

Photographic Unit

Applies specialized photographic techniques for recording and examining physical evidence

Other Crime Lab Services

Toxicology Unit- examines body fluids and organs for the presence of drugs and poisons

Latent Fingerprint Unit- processes and examines evidence for latent fingerprints

Polygraph Unit- conducts polygraph or lie detector tests Voiceprint Analysis Unit- attempts to tie a recorded

voice to a particular suspect Evidence Collection Unit- dispatches specially trained

personnel to the crime scene to collect and preserve physical evidence

Other Forensic Science Services

Forensic Pathology- concentrate closely on the understanding of types and causation of injuries and causes of sudden and unnatural death– Deals with the different stages of death

Rigor mortis- stiffening of the body (occurs within first 24 hours)

Livor mortis- settling of blood closest to the ground (occurs up to 12 hours)

Algor mortis- results in loss of heat

Other Forensic Science Services

Forensic Anthropology-concentrates on the identification of deceased individuals whose remains are decomposed, burned, mutilated or otherwise unrecognizable

Forensic Entomology- is the study of insects and their relation to a criminal investigation, commonly used to establish the time of death

Forensic Psychiatry- work with courts in evaluating an individual's competency to stand trial, defenses based on mental diseases or defects (e.g., the "insanity" defense), and sentencing recommendations

Other Forensic Science Services

Forensic Odontology- evaluates teeth to determine the identification of the deceased

Forensic Engineering- investigation of materials, products, structures or components that fail or do not operate/function as intended, causing personal injury for example

Cybertechnology- involves the examination of digital evidence

Major Crime Labs

FBI- Federal Bureau of Investigations DEA- Drug Enforcement Agency ATF- Bureau of Alcohol, Tobacco, Firearms,

and Explosives US Postal Service US Fish and Wildlife Service

The Crime Scene Team

A group of professional investigators, each trained in a variety of special disciplines

Team members include– First police officer on the scene– Medics (if necessary)– Investigator(s)– Medical examiner – Photographer and/or Field Evidence Technician– Lab Experts

Laws that Pertain to the US Criminal Justice System

The US Constitution Statutory Law Common Law or Case Law Civil Law Criminal Law Equity Law Administrative Law

US Constitution

Supreme body of laws that governs our country Overrules the constitutions of individual states

Statutory Laws

Are written laws as enacted by a government body such as Congress

Are based on the Constitution

Common Law

Also known as case law Are made by judges

– Makes for predictability and consistency in how the law is applied

Civil Law

Also known as private law Deals with relationships between individuals involving

properties or contracts– Regulates noncriminal relationships between individuals,

businesses, agency of government, and other organizations

Includes contracts, marriages, divorces, wills, property transfers, negligence, and products manufactured with hidden hazards

More concerned with assigning blame than intent

Criminal Law

Also known as public law Deals with regulation and enforcement of rights Concerned with offenses against an individual that are

deemed offensive to society– Cases tried are always the person vs the state

Those laws that are broken fall into 1 of 2 main categories– Misdemeanor- is a minor crime such as theft, minor assault and

battery, or possession of small amounts of illegal drugs– Felony- is a major crime such as murder, rape, armed robbery,

serious assaults, dealing in illegal drugs, fraud, auto theft, or forgery

Equity Law

Remedial or preventive law Are for cases not covered by common law

– Restraining orders– Injunctions

Administrative Law

Laws established by governmental agencies such as the IRS, Social Security Administration, or the military

The Bill of Rights

The right to be presumed innocent until proven guilty The right not to be searched unreasonably, either on

one’s person or in one’s home The right not to be arrested without probable cause The right against unreasonable seizure of personal

property The right against self-incrimination The right to fair questioning by police

The Bill of Rights

The right to protection from physical harm throughout the justice process

The right to an attorney The right to trial by jury The right to know any charges against oneself The right to cross examine prosecution

witnesses The right to speak and present witnesses

The Bill of Rights

The right not to be tried again for the same crime The right against cruel and unusual punishment The right to due process The right to a speedy trial The right against excessive bail The right against excessive fines The right to be treated the same as others, regardless

of race, gender, religious preference, country of origin, and other personal attributes

Steps in Pursuing Justice

If a crime is committed these are the steps to take while pursuing justice

– Police investigate what happened– Information is collected– Crime scene is documented and searched for evidence– All info is assembled into a report and sent to DA– Investigation continues until probable cause is established– An arrest warrant is issued for the suspect– The suspect is arrested

Individual is booked, fingerprinted, photographed and informed about his/her rights

The Miranda Rights

Miranda v. Arizona (1966)– Before a law enforcement officer may question a

suspect regarding the possible commission of a crime, he or she must inform the detainee about his or her Miranda rights, making sure the detainee understands them

The Miranda Rights

Warning of Rights– You have the right to remain silent and refuse to answer questions– Anything you do or say may be used against you in the court of law– You have the right to consult an attorney before speaking to the police

and to have your attorney present during questioning now or in the future

– If you cannot afford an attorney, one will be appointed for you before any questioning if you wish

– If you decide to answer questions now without an attorney present, you will still have the right to stop answering at any time until you talk to an attorney

– Knowing and understanding your rights as I have explained them to you, are you willing to answer my questions without an attorney present?

Steps in Pursuing Justice

– Person is brought before a magistrate judge who informs the individual of the charges, his/her rights, and bail

The person may also enter a plea of guilty, not guilty, not guilty by reason of insanity, double jeopardy (been tried for same crime in same court), or nolo contendere (no contest)

– If a plea of guilty is entered, the person is brought before a preliminary or evidentary hearing (no jury present)

Most states use a grand jury– Will determine if there is enough evidence to bring the accused to a

formal trial– The prosecutor presents evidence and the grand jury (16-23 citizens)

decide the fate of the accused– If the grand jury decides there is enough evidence, a trial date will be

set

Steps in Pursuing Justice

– If a plea of not guilty by reason of insanity is entered, the defendant will have to prove, by “clear and convincing evidence,” that “at the time of the commission of the acts constituting the offense, the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or wrongfulness of his acts”

Crimes must show intent- the insanity plea removes intent

Steps in Pursuing Justice

– Sometimes, the DA will plea bargain with the accused

The defendant works out a deal with the DA– May reduce jail time

Types of Crimes

All crimes are violations (breach of a right, duty, or law)– 3 types

Infractions Misdemeanors Felonies

Infractions

Minor offense or petty crime Is less serious than a misdemeanor Examples include

– Jaywalking– Traffic violations– Littering

Penalty is usually a fine

Misdemeanors

Cases are tried in court Punishable by no more than 1 year in jail Examples include

– A first offense of drunk driving, vandalism, shoplifting, simple assaults, trespassing, or prostitutions

Fines range from less than $250 to $2500 Community service is also part of the sentence

sometimes

Felonies

Cases are tried in court Punishable from 5 years to life

– Some states offer death penalty Examples include

– Arson, aggravated assault, burglary, robbery, homicide, and rape

Fines may be up to $100,000 Probation may also be determined

Federal Rules of Evidence

Probative– In evidence law, tending to prove something

Material– In evidence law, relevant and significant.

Hearsay – Testimony given by a witness who relates not what

he or she heard, saw, or knew personally, but what others have said

– Is not admissable in the court of law

Admissibility of Evidence

1923 Frye v. US– Scientific evidence is

allowed into the courtroom if it is generally accepted by the relevant scientific community.

– The Frye standard does not offer any guidance on reliability.

– The evidence is presented in the trial and the jury decides if it can be used.

1993 Daubert v. Dow– Admissibility is determined by

Whether the theory or technique can be tested

Whether the science has been offered for peer review

Whether the rate of error is acceptable

Whether the method at issue enjoys widespread acceptance

Whether the opinion is relevant to the issue

– The judge decides if the evidence can be entered into the trial

Facets of Guilt

Try to prove– Means- person had the ability to do the crime– Motive- person had a reason to do the crime

Does not have to be proved in a court of law

– Opportunity- person can be placed at the crime