Download Forensic Science

Forensic Science
Criminalistics
Chapter 1:
Introduction
What is Forensic Science?
The application of science and technology
to criminal and civil laws.
These laws are enforced by police agencies
in a criminal justice system.
Major Sciences Involved in
Forensics
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Chemistry:
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examines the chemical makeup of substances
found at the crime scene
Biology:
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examines the biological properties of
substances found at the crime scene
Major Sciences Involved in
Forensics
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Physics:
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examines the movement or impact of
materials at the crime scene
Geology:
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examines the earth’s components when
important to the crime scene investigation
History of Forensics

Sir Arthur Conan Doyle
Fictional character –Sherlock Holmes
 The character, Sherlock Holmes, first applied
these principles in Doyle’s novels:

 Serology
 Fingerprinting
 Firearm
Identification
 Questioned-document examination
History of Forensics

Mathieu Orfila (1787-1853)
Father of Forensic Toxicology
 Spanish native—taught medicine in France
 Published “The Detection of Poisons and
Their Effects on Animals” which established
Forensic Toxicology as a legitimate scientific
endeavor

History of Forensics

Alphonse Bertillon (1853-1914)
Father of Personal Identification or Criminal
Identification
 The science of anthropometry: a systematic
method of taking body measurements
 Anthropometry was eventually replaced by
fingerprinting in the early 1900s

History of Forensics

Francis Galton (1822-1911)
Studied fingerprints and developed a method
of classifying them
 Proved the uniqueness of individual
fingerprints and their use for personal
identification
 His ideas describe the principles used today
in fingerprinting

History of Forensics

Leone Lattes (1887-1954)
Developed the concept that blood typing
could be a useful identification tool in criminal
investigation
 Devised a simple procedure for determining
the blood group from a dried blood stain

History of Forensics

Calvin Goddard (1891-1955)
Colonel in the United States Army
 First used a microscope to determine if a
bullet was fired from a certain firearm
 Established the Comparison Microscope as
an indispensable tool in forensic
investigations

History of Forensics

Albert S. Osborn (1858-1946)
Development of the fundamental principles of
document examination
 Was responsible for the acceptance of
document examinations as scientific evidence
by courts of law
 Authored “Questioned Documents” –a book
still used in the field of document examination
today

History of Forensics

Walter McCrone (1916-2002)
Applied using microscopes to all fields of
forensic investigations
 Taught numerous forensic scientists how to
use quantitative analysis methods in forensic
investigations

History of Forensics

Hans Gross (1847-1915)
Authored the first treatise describing the
application of scientific disciplines to the field
of criminal investigation
 Detailed the assistance that investigators
could expect from the numerous fields of
science

History of Forensics

Edmond Locard (1877-1966)
Strong advocate of the use of the scientific
method in criminal investigation
 Background in Medicine and in Law
 Taught how scientific principles could be
developed into a workable crime laboratory
 Famous for Locard’s Exchange Principle

Locard’s Exchange Principle
The exchange of materials between two
objects that occurs whenever two objects
come into contact with one another
Locard’s Exchange Principle

Examples:
Metal particles carried on clothing from a
crime scene can link a suspect to a crime
 Soil samples found on the vehicle of a
suspect can link the suspect to a crime scene
 Plant material found on cars or clothing can
link a suspect to a crime scene

Ch. 1 Sec. 1 Review Questions
1) What is forensic science?
 2) What is the difference between biology
and chemistry?
 3) What is the difference between geology
and physics?
 4) What is anthropometry?
 5) Why is anthropometry not used in
modern forensics?

Ch. 1 Sec. 1 Review Questions
6) What is Sir Author Conan Doyle famous
for?
 7) _______ is the father of forensic
toxicology.
 8) _______ is the father of personal
identification.
 9) Who developed document
examination?
 10) What is Locard’s Exchange Principle?

Forensic Investigations Video
Questions
How was the “Iceman” killed?
 How was this theory tested?
 How was Toms linked to the murder?
 What was his punishment?
 Why did detectives take the temperature
of the dead body?
 How was swabbing Toms’ face for
gunpowder residue useful in the
investigation?

Forensic Investigations Video Part
2: Review Questions
1) How old was the skeleton that was
discovered?
 2) What is a biased article?
 3) Why did investigators decide that the
skull could not be Native American?
 4) How many tribes claimed the skull as
their own?
 5) What do you think should happen to the
remains?
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Beginnings of Crime Labs

The oldest crime lab in the United States
was established by the Los Angeles Police
Department in 1923 under the Director
August Vollmer
The Federal Bureau of
Investigation
1932
 Director: J. Edgar Hoover
 Organized a national crime lab to provide
forensic services to all law enforcement
agencies in the country

The Federal Bureau of
Investigation
The FBI Laboratory is now the world’s
largest forensic laboratory, performing over
one million examinations per year
The Federal Bureau of
Investigation

Opened the Forensic Science Research
and Training Center in 1981

Center is dedicated to conducting
research and developing new and reliable
scientific methods that can be applied to
forensic science
Chapter 1 Section 2 Review
Questions

1) Who established the oldest crime lab in
the U.S. and in what year?

2) What was Edmond Locard famous for?
Explain you answer.

3) Give an example of how Locard’s
Exchange Principle could be used to solve
a crime. (Think of one on your own.)
Chapter 1 Section 2 Review
Questions

4) What is the major responsibility of the
FBI?

5) Why is it important that the FBI provides
“forensic services” to law enforcement
agencies all over the country?

6) What sort of “forensic services” would
they provide? Come up with 3 examples.
Ch. 1 Sec. 1-2 Vocabulary

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
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Forensic Science
Chemistry
Biology
Physics
Geology
Anthropometry
L.E.P.
Homicide
Theory
Law
Forensic Vocabulary
Homicide: the act of killing another human
being
 Theory: an ideal or hypothetical set of
facts, principles, or circumstances
 Law: system of rules or guidelines that are
enforced through social institutes to
govern behavior
 Exact: not approximated in any way;
precise

The Organization of a
Crime Laboratory
Forensic Vocabulary Review
1) ________: examines the chemical
makeup of objects at the crime scene
 2) ________: examines the biological
makeup of objects at the crime scene
 3) ________: a systematic method of
taking body measurements
 4) ________: the exchange of materials
between 2 objects whenever 2 objects
come into contact with one another

Forensic Vocabulary Review
5) _________: not approximated in any
way; precise
 6) _________: the act of killing another
human being
 7) _________: the application of science
and technology to criminal and civil laws
 8) _________: examines the Earth’s
components when important to the crime
scene investigation

Forensic Vocabulary Review
9) ________: examines the movement or
impact of materials at the crime scene
 10) _______: an ideal or hypothetical set
of facts, principles or circumstances
 11) ________: a system of rules or set of
guidelines that are enforced through social
institutes to govern behavior

Crime Labs

Can be under the direction of …
The Police Department
 The Prosecutors or District Attorney’s Office
 The Coroner or Medical Examiner’s Office
 Universities as independent testing facilities

Crime Labs
Range in size and in the number of staff
members
 Can be classified under several
jurisdictions

Federal
 State
 County
 Municipal

Crime Labs

There are approximately 320 public crime
labs operating in various jurisdictions

These crime labs range being able to
perform a diversity of tasks to very
specialized scientific testing
Growth of the Crime Lab

Some Reasons:
Courts placing greater emphasis on scientific
evidence
 Emphasis on thorough and complete police
investigations
 Increase in modern technology and types of
testing that can be completed

Growth of the Crime Lab

Major Reasons:

Increase in the crime rates in the United
States
 Even
though many crimes do not require forensic
evaluation of evidence
Growth of the Crime Lab

Major Reasons:

The increased number of drug-related arrests
 All
seizures must be sent to the lab for
confirmation of chemical composition of the
substance
 More drug arrests=Larger case loads of drugrelated specimens
Growth of the Crime Lab

Major Reasons:
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The advent of DNA Profiling
 Labor-intensive
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tests for DNA analysis
May come from blood evidence
May come from saliva
May come from bite marks, cigarette butts, hair, etc.
Federal Crime Labs in the U.S.
Will assist any local agency that requests
assistance in investigative matters
Federal Crime Labs in the U.S.

Federal Bureau of Investigation (FBI)
Housed under the Department of Justice
 Responsibilities:

 Broad,
investigative powers that exceed
jurisdictions of state and local authorities
 Expertise and technology support for criminal
investigations
Federal Crime Labs in the U.S.

Drug Enforcement Agency (DEA)
Housed under The Department of Justice
 Responsibilities

 Analysis
of drugs seized in violation of federal laws
that regulate the production, sale, and
transportation of drugs in the U.S.
Federal Crime Labs in the U.S.
Bureau of Alcohol, Tobacco, Firearms, and
Explosives (ATF)
 Housed under The Department of Justice


Responsibilities:
 Analyzing
alcoholic beverages and documents
relating to tax law enforcement
 Examining weapons, explosive devices, and
evidence relating to the Gun Control Act of 1968
and the Organized Crime Control Act of 1970
Federal Crime Labs in the U.S.

U.S. Postal Inspection Services
Housed under The Department of Justice
 Responsibilities:

 Investigates
service
criminal acts relating to the postal
State Crime Labs in the U.S.
Most states have crime labs to assist local
law enforcement agencies that do not
have easy access to a crime lab
State Crime Labs in the U.S.
Some states, such as Alabama, have
developed a comprehensive statewide
system of crime labs with satellite facilities
Maximizes access to lab services without
duplicating services at each site
Sharing of expertise and
equipment
Ch. 1 Sec. 3 Review Questions
1) Who established the oldest crime lab in
the U.S. and in what year?
 2) What is the major responsibility of the
FBI?
 3) Why is it important that the FBI provides
“forensic services” to law enforcement
agencies all over the country?
 4) What is the ATF and what is its major
responsibility?

Ch. 1 Sec. 3 Review Questions
5) What is the DEA and what is its major
role?
 6) List the 3 major reasons for the growth
of crime labs in the U.S.
 7) There are approximately ____ crime
labs operating in various jurisdictions.
 8) List the 4 levels of jurisdictions.

Case Study # 1

A murder has occurred in a suburb of Atlanta. A
family of 4 has been found in their home. Police
arrived at the scene around 8:30 in the morning
after a neighbor discovered the bodies. The
neighbors report not hearing noise the night of
the crime. The glass side door to the home has
been broken and the home has been robbed as
well. The family’s car still remains in the
driveway. The only evidence found at the crime
scene is a small drop of blood beside the broken
glass.
Case Study # 1
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1) Where did the murder occur?
2) How many bodies were found?
3) Who discovered the bodies?
4) What is the point of entry to the home?
5) What evidence was found at the crime?
6) How can investigators use the evidence to
help solve the crime?
7) Is there any importance to the family car still
being in the driveway? If so, what?
Notebook Quiz
1) What is forensic science?
 2) Why are Goddard and Lattes famous?
 3) What is the responsibility of the ATF?
 4) List 3 major reasons for the growth of
crime labs.
 5) How many crime labs are there in the
U.S.?
 6) List the 4 jurisdictions that crime labs
can be classified as.

Notebook Quiz
7) What is anthropometry?
 8) What is Locard’s Exchange Principle?
 9) Who was the director of the FBI in
1932?
 10) Who was the oldest crime lab in the
U.S. established by?

Services of the Crime Lab
Variation in Services
There are many different services
available in different crime labs
 Reasons:

Variations in local laws
 Different capabilities and functions of the
organization in which the lab is attached
 Budgetary and staffing limitations

Full-Service Crime Lab: 5 Parts

Physical Science Unit
Applies the principles of chemistry and
physics to crime-scene evidence.
 Examples:

 Drug
Chemistry Identification
 Soil/Mineral Analysis
 Physical Properties of Trace Evidence
Full-Service Crime Lab: 5 Parts

Biology Unit
Apply their knowledge to biological aspects of
a crime scene
 Examples:

 Identification
and DNA profiling of dried blood
stains
 Hair and fiber comparison
 Identification of plant material
Full-Service Crime Lab: 5 Parts

Firearms Unit
Responsible for the examination of firearms,
discharged bullets, cartridge cases, shotgun
shells, and ammunition of all types
 Examples:

 Examination
of ammunition casings
 Firearm or gunpowder residue
 Target length
 Toolmarks
Full-Service Crime Lab: 5 Parts

Document Examination Unit
Studies the typewriting and handwriting on
questioned documents to determine
authenticity and/or source
 Examples:

 Handwriting
identification
 Analysis of ink or paper
 Indentations
 Erasure marks
Full-Service Crime Lab: 5 Parts

Photography Unit
Used to examine and record physical
evidence
 Examples:

 Digital
imaging
 Infrared imaging
 Ultraviolet imaging
 X-ray photography
Crime Lab Optional Services
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Toxicology Unit:
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Latent Fingerprint Unit
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Determines the presence or absence of drugs
or poisons
Processes and examines evidence for latent
fingerprints
Polygraph Unit
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Administers lie detector tests to suspects
Crime Lab Optional Services
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Voiceprint Analysis Unit
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Analyzes tape-recorded messages or
telephoned threats
Evidence Collection Unit
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Collects and preserves evidence at the crime
scene
Forensic Vocabulary

Latent fingerprint: marks left at a crime
scene not immediately visible

Toxicology: branch of science concerned
with the study of adverse effects of
chemicals in living organisms

Trace evidence: evidence that occurs
when different objects contact one another
Chapter 1 Section 4: Review
Questions
1)
2)
3)
4)
List 2 reasons that there is a variation in
services from one crime lab to the next.
What job does the physical science unit
have at a crime scene?
List 2 specific examples of what the
biological unit would inspect at a C.S.
What is meant by “target length?”
Chapter 1 Section 3 Pop Quiz
5) List 2 things that Document Examination teams
investigate.
6) What does toxicology refer to?
7) What are “latent” fingerprints?
8) ________ _______ test is another name for
polygraph test.
9) Out of all 5 crime lab optional services, in your
opinion which is the most important at any
general crime scene? Why is this service more
important that the others?
Case Study # 4
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A hit-and-run has occurred in downtown Atlanta
during the middle of the night. The owner of the
damage car was awakened at the sound of the
crash. When he looked out his apartment
window, the suspect was gone. The owner
quickly rushed downstairs where he examined
his car closer. There were 2 distinct spots on the
owner’s white car where red paint from the crash
had been left. The owner also noticed tire marks
in the road from where the suspect sped away.
There were no witnesses to the crime.
Case Study # 4: Review Questions
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1) What evidence was left at the crime scene?
2) What type of crime has occurred?
3) How many witnesses were there?
4) What color car did the owner have?
5) What color car did the suspect have?
6) What principle could investigators apply to
solve this case?
7) Using the evidence at the crime scene, is it
possible for investigators to solve this crime?
Why or why not?
Case Study # 5

An arson has occurred at City Hall in
downtown Phoenix. Firefighters were
called to the scene but were unable to
salvage much of the building. Investigators
discover a gasoline canister and a silver
lighter in the alley. The canister is empty
and a partial print is able to lifted from the
lighter. There are no witnesses to the
crime and no injuries were reported.
Case Study # 5: Review Questions
1) What is arson?
 2) Is arson a crime? Why or why not?
 3) Were there any pieces of evidence
recovered? If so, what?
 4) Was there any damage done to the
building? If so, how much?
 5) If you were leading this investigation,
how would you attempt to solve it?

Section 5 Part A: The
Functions of the Forensic
Scientist
Forensic Scientists
Must be skilled in applying the principles and
techniques of the physical and natural
sciences to the analysis of many types of
evidence that may be recovered at a crime
scene
Forensic Scientists
- Must have a solid, scientific foundation.
- Must follow specific procedures in order
for evidence to be admissible in court.
Frye v. United States

Court case that established what type of
rules scientific evidence have to follow
Scientific procedures will only be allowed in
court if they are “generally accepted by the
scientific community”
 Helps establish the accuracy and validity of
the tests and the results easy to understand
by all scientists.
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“Generally Accepted Procedures”
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How are “generally accepted procedures”
determined?
Expert witnesses
 Books
 Documented studies
 Case history

Daubert v. Merrell Dow
Pharmaceutical, Inc.
Court case in 1993
 Asserted that “general acceptance” is not
an absolute prerequisite for admissibility
 The judge in the case can be a
“gatekeeper” in deciding the admissibility
and reliability of scientific evidence that is
presented in a courtroom

Daubert Precedence Guidelines

Guidelines to gauge the scientific evidence
Whether or not the method has been or can
be tested
 Whether or not the method has been
published or reviewed by others in the field
 The technique’s potential rate of error
 Standards of operational procedures
 Acceptance in the general scientific
community

Kumho Tire Co. v. Carmichael
The trial judge’s “gatekeeping” rule applies
to not only scientific evidence but also to
expert testimony
Coppolino v. State
Widened the discretion of the trial judge
 New scientific tests can be used in
evidence if no other tests can be or ever
have been performed

Must have valid principles and techniques
 Give examiners the flexibility to develop new
and better methods of testing samples

Case Study # 6
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2 bodies have been found in a remote
wooded area outside the Chicago city
limits. A tire track from an unknown vehicle
has been found at the scene. The police
received a tip that a tan car was seen
leaving the area and speeding away
around the time of the murders. Police
have narrowed the search to 3 suspects,
all of which have tan cars.
Case Study # 6: Review Questions
1) How many bodies were found?
 2) Outside what city did the crime occur?
 3) What was the only evidence at the CS?
 4) How did police narrow the list of
suspects?
 5) How many suspects do the police
have?
 6) If you were leading the investigation,
how would you find the killer?

Case Study # 7
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You have received an anonymous tip from a
caller at the police station in downtown Dallas.
The tip involves a 10 year old murder
investigation that was never solved. The caller
describes her neighbor who works for a
construction company. The caller also claims to
have seen the victim at the neighbor’s house
mutliple times before going missing. The
neighbor works during the day and is always
doing landscaping work at odd hours of the night
in his backyard.
Case Study # 7: Review Questions
1) What type of crime has occurred?
 2) In what city does the crime take place?
 3) How long has the crime been unsolved?
 4) Where does the suspect work?
 5) What is odd about the suspect?
 6) If you were leading this investigation,
how would you attempt to solve this
crime?
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What is an Expert Witness?
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Expert witnesses
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Have knowledge, skill, experience, training, or
education that lends itself directly to
understanding of scientific evidence
What is an Expert Witness?

Expert witnesses are “qualified” for
testimony in a courtroom by:
Degrees awarded
 Special courses
 Professional societies
 Publications
 Occupational experience

What is an Expert Witness?

Most experts do not have Forensic
Science degrees
Most have degrees in specific science
discipline
 Training and experience is a big part of being
“qualified” as an expert witness

More about experts…

Experts are the only people who may give
testimony as opinions in court
Opinions must be based on facts and data
 Opinions must be based on reliable principles
and methods
 Opinions must apply the facts and principles
directly to the case at hand

Expert Witness Testimony
Evaluate evidence that the court lacks
expertise to do
 Express an opinion of the significance of
the findings
 May be accepted or ignored in jury
deliberations
 Experts have no absolute certainty—their
opinions come from training or experience

Opposing an Expert Witness
Weakness in background knowledge
and/or educational experience
 Inability to explain data clearly and
logically
 Suitable qualifications are subjective
 Demeanor of the expert witness in the
courtroom

Lay v. Expert Witnesses

Expert witnesses may express opinions in
the courtroom


May or may not be dismissed by the jury or
judge
Lay witnesses may only express facts in
the courtroom

Facts must be taken into account by the jury
or judge
Section 5 Part B: Evidence
Collection Team
Evidence Collection is Important!
Must be collected correctly and preserved
 Some labs have Evidence Collection
Teams or Crime Scene Investigators

Trained by lab staff to gather important
physical evidence at the scene
 Work in the lab to continue their exposure to
the forensic procedures
 Use proper tools and supplies for collection
and packaging of evidence

Collecting Evidence

Sometimes specialized teams aren’t
available for evidence collection

Detectives can also collect evidence
 Effective
based on training and experience
 Classroom knowledge is necessary but experience
is best
Collecting Evidence

Every officer should be trained in fieldwork
Some officers specialize in different fields
 Some of the different fields are:

 Traffic
 Patrol
 Investigation
 Evidence
Collection
Collecting Evidence
All officers should be familiar with:
 Classroom Lectures
 Forensic Lab Tours
 Manuals for methods of submission of
evidence to the lab
Chapter 1 Sec. 5 Part B Review
Questions
1) List 3 reasons expert witnesses are considered
qualified.
2) ________ ________ are the only people that
may give testimony as opinions in court.
3) What is the difference between an expert and a
lay witness?
4) ______ can also collect evidence.
5) List 4 of the different fields that investigators
may work in.
Case Study # 8
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A body has been found in the upper east
side of Manhattan. Amazingly, no evidence
can be found at the CS. Police arrived at
the scene after responding to a frantic
phone call from someone who found the
body. The cause of death cannot be
determined by investigators. There are no
suspects in the case.
Case Study # 8: Review Questions
1) What type of crime has been occurred?
 2) What evidence has been found?
 3) How many suspects do police have?
 4) If you were an investigator, how would
you try to determine the time of death?
 5) If you were an investigator, how would
you determine the cause of death?
 6) If you were an investigator, how would
you try to find a suspect?

Other Forensic Science
Services
Forensic Pathology
Field that involves the investigation of
sudden, unnatural, unexplained, or violent
deaths
 Involve the Medical Examiner or Coroner
and generally perform autopsies on
victims

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Autopsy: the medical dissection and
examination of a body in order to determine
the cause of death
Forensic Pathology

Must answer the questions…
Who is the victim?
 What injuries are present?
 When did the injuries occur?
 Why and how were the injuries produced?

Forensic Pathology
Must determine the manner of death of the
victim
 Manners of death
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 Natural
 Homicide
 Suicide
 Accident
 Undetermined
Determining Time of Death

Stages of Decomposition

1) Rigor Mortis:
 occurs
after death and results in the shortening of
muscle tissue and the stiffening of body parts in
the position they are in when death occurs
 Happens in the first 24 hours and disappears
within 36 hours
Determining Time of Death

Stages of Decomposition

2) Livor Mortis:
 Occurs
in the early stages of decomposition and
results when the heart stops pumping and blood
pools in the parts of the body closest to the ground
 Skin will appear dark blue or purple in these areas
 Condition appears immediately and continues for
up to 12 hours after death
 Skin will not appear discolored in areas where the
body is restricted by either clothing or an object
pressing against the body
Determining Time of Death

Stages of Decomposition:

3) Algor Mortis:
 Process
in which the body temperature continually
cools after death until it reaches the temperature of
its’ surroundings
 General rule: the body will lose heat, beginning an
hour after death, at a rate of 1 to 1.5 degrees F per
hour until the environmental temperature is
reached
 Influenced by weather/clothing conditions
Determining Time of Death

4) Potassium levels in the ocular fluid
After death, cells release potassium into the
liquid behind the eye
 By analyzing the amount of potassium
present at various intervals after death, the
rate of potassium release can be determined
 Can help the pathologist to approximate the
time of death

Forensic Anthropology
Identification and examination of skeletal
remains
 May reveal personal attributes such as
origin, sex, age, race, and/or injury
 Facial reconstruction
 May be able to identify mass victims of
disaster through skeletal remains

Forensic Entomology
The study of insects and their relation to a
criminal investigation
 As decomposition occurs, insects arrive on
the carcass in a regular time interval
 May help determine time of death
 Results may be effected by geographical
location, climate, and weather conditions

Life Cycle of a Fly
Forensic Psychiatry
Area in which the relationship between
human behavior and legal proceedings are
examined
 Civil cases: competency to make
decisions
 Criminal cases: competency to stand trial
 Profilers: track the behavior of criminals
based on patterns and types of crimes

Forensic Engineering
Concerned with failure analysis, accident
reconstruction, and causes and origins of
fires or explosions
 Focus mainly on the logical sequence and
main cause of an accident or crime
 Also attempts to determine who or what is
responsible for the cause of an accident or
crime

Forensic Odontology
Provide information about the identification
of victims when the body is left in an
unrecognizable state
 Dental records

Characteristics of teeth
 Teeth alignment
 Overall structure of the mouth


Bite mark analysis in assault cases
Chapter 1 Pop Quiz
1) List 2 rules that must be followed when
collecting evidence.
2) (True/False) Detectives can also collect
evidence.
3) What is forensic pathology?
4) What is an autopsy?
5) List the 2 most important questions of a
forensic pathologist.
Chapter 1 Pop Quiz
6) Rigor mortis happens within the first
_____ hours of death and disappears
within ______ hours.
7) What is the difference between livor and
algor mortis?
8) Where is ocular fluid located?
9) How can examining potassium levels help
approximate time of death?
10) What is forensic anthropology?
Chapter 1 Notebook Quiz
1) What is the difference between forensic
anthropology and forensic engineering?
 2) List 4 ways to tell a victim’s time of
death.
 3) What is an autopsy?
 4) What is the difference between a lay
and an expert witness?
 5) What is a profiler?
