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
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
Crime Lab Services

5 exist
–
Physical science



–
–
–
–
Chemistry
Physics
Geology
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 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
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




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
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
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







pathologist
serologist
DNA expert
toxicologist
forensic odontologist
forensic anthropologist
forensic psychologist
forensic entomologist
firearm examiner
bomb and arson expert
document and handwriting experts
fingerprint expert
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
–

Examples include
–


Some states offer death penalty
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
–

Material
–

In evidence law, tending to prove something
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