Transcript Chapter 1 - Introduction

Chapter 1 - Introduction
Basics of Forensic Science
Definition and Scope
 Forensic science is the application of
science to law:
 Applies the knowledge and
technology of science to the
definition and enforcement of
laws
 Laws are continually being
broadened and revised to
address the alarming increase
in crime rates
The Role of Science
 Science cannot offer final and
authoritative solutions to all
problems
 Social and psychological factors are
always present
 Science plays an important and
unique role in the criminal justice
system – ability to supply accurate
and objective information that
reflects events that have occurred
at a crime scene
Definition of Forensics Science
 The application of science to
the to the criminal and civil
laws that are enforced by
police agencies in a criminal
justice system.
Diversity of Professions Involved
 According to the American Academy of Forensic
Science:
 Criminalistics (synonym for forensic science)
 Engineering Science
 General
 Jurisprudence
 Odontology
 Pathology/Biology
 Physical Anthropology
 Psychiatry/Behavioral Science
 Questioned Documents
 Toxicology
Additions to the list of 10:
 Fingerprint examination
 Firearm and tool mark
examination
 Technology analysis
 Computers
 Digital data analysis
 Photography
History and Development
 Individuals who developed the
principles and techniques needed
to identify or compare physical
evidence
 Those who recognized the need to
merge these principles into a
coherent discipline that could be
practically applied to a criminal
justice system
Early Developments
 One of the earliest records:
 3rd century China – manuscript Yi Yu Ji
 Case solved where a woman was suspected
of murdering her husband
 Evidence showed that he was murdered
and she admitted her guilt
 Chinese were also the first to recognize the
potential of fingerprints for identification
purposes
 Often the exception rather than the rule for
criminal investigations
Early Developments (continued…)
 Limited knowledge of anatomy
and pathology
 Hampered the development of
Forensic Science until late 17th and
early 18th centuries
 First recorded notes about
fingerprint characteristics
 1686, Marcello Malpighi
 Did not acknowledge the value of
fingerprints as a method of ID
Initial Scientific Advances
 1798; “A Treatise on Forensic
medicine and Public Health”
 François-Emanuel Fodéré
 Breakthroughs in chemistry also
helped
 1775; Carl Wilhelm Scheele devised
first successful test for detecting
arsenic in dead bodies
Initial Advances (continued…)
 1814; Mathieu Orfila
 Father of forensic toxicology
 Published the first scientific treatise
(study) on the detection of poisons and
their effects on animals
 Mid-1800s
 Advance of several scientific disciplines
which advanced the field of forensics
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1828; William Nichol – polarizing microscope
1839; Henri-Louis Bayard – microscopic detection of sperm
1839; toxicological evidence first used at a trial
1853; microcrystalline test for hemoglobin
1863; first presumptive test for blood
1850s and 1860s; use of photography in forensics
Late 19th-Century Progress
 Beginning to apply knowledge from all
scientific disciplines to the study of
crime
 Anthropology/Morphology (structures
of living organisms) applied to the first
system of personal identification
 1879; Alphonse Bertillon
 Named anthropometry – systematic
procedure for using a series of body
measurements as a means of distinguishing
one person from another (later replaced by
fingerprinting)
 Father of Criminal Investigation
More on the 19th century…
 Bertillon’s anthropometry later
replaced by fingerprinting
 Thomas Taylor (American) said that
fingerprints could be used for ID
 Supported by Scottish physician
Henry Faulds
 1892; Francis Henry Gaulton
undertook the first definitive study
of fingerprints and developed a
method for classifying them
Sherlock Holmes
 Not a real person
 Legendary but fictional detective in
stories by Sir Arthur Conan Doyle
 Had a considerable influence on
popularizing crime-detection methods
 Applied newly developing principles of
serology (blood/body fluids),
fingerprinting, firearms ID and
document analysis in his stories
 Doyle’s “A Study in Scarlet” is a classic
example (see excerpt)
20th Century Breakthroughs
 1901; Karl Landsteiner
 Discovered ABO blood types
 1910; Albert S. Osborne
 Wrote the first significant text on Questioned
Documents (document examination)
 1915; Dr. Leon Lattes
 Developed a simple procedure for identifying
the blood group from a dried blood stain
 Immediately applied to criminal investigations
 Acceptance of documents as scientific evidence
by the courts
 1923; Calvin Godddard
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Used comparison microscope to refine techniques of
firearms examination
Edmond Locard
French
Formal education in both medicine and law
Started the first police lab in 1910
Founder and director of the Institute of
Criminalistics @ the University of Lyons (France)
 Leading international center for study and
research in forensic science
 Strongly believed every criminal can be
connected to a crime by dust particles carried
from the crime scene
 Locard’s successes helped start police labs in
Vienna, Berlin, Sweden, Finland and Holland
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Locard’s Exchange Principle
When two objects (or
people) come in
contact with each
other, a cross-transfer
of materials occurs
Modern Scientific Advances
 Mid-20th century
 Revolution in computer technology
 Dramatically impacted the field of forensics
 Wide array of sophisticated techniques for
analyzing evidence available
 Chromatography
 Spectrophotometry (measuring the
absorption/reflection of light by materials)
 Electrophoresis
DNA
 Most significant modern advance
 DNA typing and profiling
 1984; Sir Alec Jeffries developed the
first DNA profiling test
 1986; DNA profiling used to solve the
“Pitchfork” murders of two young
English girls (Colin Pitchfork)
 Precise ID of a suspect can be
determined
Computer Databases
 Fingerprints
 Bullets and shell casings
 DNA
 Significantly reduced the time it
takes to analyze evidence and
increase accuracy of the results
Key Points:
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Forensic science is the application of science to
criminal and civil laws that are enforced by police
agencies in a criminal justice system
The first system of criminal ID was called
anthropometry. It distinguished one individual from
another based on a series of body measurements
Forensic science owes its origins to individuals such
as Bertillon, Gaulton, Lattes, Goddard, Osborne and
Locard, who developed the techniques needed to
identify or compare physical evidence.
Locard’s Exchange Principle states that when two
objects come in contact with each other, a crosstransfer of materials occurs that can connect a
criminal suspect to his/her victim.
Crime Laboratories - History
 1923; Los Angeles Police Dept. crime lab is the
oldest
 Established by August Vollmer
 1948; School of Criminology formed at UCBerkley
 1932; FBI established under President Herbert
Hoover
 Offered forensic services to all law enforcement
agencies in the USA
 1981; Forensic Science research and Training
Center for research and development of new
techniques/tools/methods
 Train lab personnel in the latest techniques
 Most labs are run locally or at the state level
Organization of a Crime Lab
 Characterized by rapid growth
 Lack of national/regional
planning/coordination
 Levels: federal, state, county,
municipal
 Size and diversity makes it impossible
to adopt a single model of operation
 Most function as part of the local police
department, prosecutor, district
attorney or medical examiner
(coroner)
Growth
 Several reasons explain the rapid
growth of crime labs in the past 40
years
 Supreme Court decisions requiring
scientific, objective treatment of evidence
 Constitutional rights of suspects (Miranda
Rights)
 Changing judicial requirements due to the
staggering increase in crime rates in the
USA, especially drug-related crime
 DNA technology/profiling needs more
qualified personnel to analyze the evidence
 Drug cases still outnumber DNA cases
Crime Labs in the USA
 Desire to retain local control
 Produced a variety of
independent labs
 Government has no single law
enforcement agency with
unlimited jurisdiction
Crime Labs in the USA (continued)
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FBI (Department of Justice)
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Maintains the largest crime lab in the world
Ultramodern facility located in Quantico, VA
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Analyzes drugs seized in violation of federal laws regulating
production, sale and transport
DEA (Drug Enforcement Administration - (Department of
Justice)
ATF (Alcohol, Tobacco and Firearms)
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4.
Analyzes alcoholic beverages
Examines documents related to alcohol and firearm excise tax
law enforcement
Examines weapons, explosive devices and related evidence
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Gun control Act of 1968
Organized crime Control Act of 1970
U.S. Postal Service
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Criminal investigations related to the postal service
Local and International Crime Labs
 Most state governments maintain a
crime lab some wit regional or satellite
offices (larger states)
 Try to be cost-effective by not duplicating
services
 Most countries have created and
maintain facilities
 Organization can vary from country to
country
 Often operate on a fee-for-service basis
(some can be private companies)
Services of the Crime Lab
 Wide variation in total services
offered
 There are many reasons for this
 Variations in local laws
 Different capabilities/functions of the
organization to which the lab is
attached
 Budgetary and staffing limitations
(often very limited)
 Some labs have strict functions like
processing drug specimens only
Basic Services
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Physical Science Unit
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Principles of chemistry, physics and geology
ID/comparison of crime-scene evidence
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Biologists/biochemists
DNA profiling, ID/comparison of biological evidence including
botanical materials
Biology Unit
Firearms Unit
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Examines firearms, discharged bullets, cartridge cases, shotgun
shells, ammunition, residues, tool marks
Determine composition, distance, angles
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Handwriting/typewriting on questioned documents
Ascertain authenticity/source
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Examines/records photographic evidence
Uses highly specialized techniques such as digital imaging, IR,
UV, X-ray to make invisible images/information visible
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Document Examination Unit
Photography Unit
Optional Services Provided by a Fullservice Crime Lab
 Toxicology Unit
 Examines body fluids/organs to determine the
presence/absence of drugs
 Latent Fingerprint Unit
 Processes and examines fingerprint evidence
 Polygraph Unit
 Lie detecting
 Voiceprint Analysis Unit
 Involves cases of telephone threats or recorded
messages
 Trained analysts tie the voice to a suspect
 Sound spectrograph creates a voiceprint
 Sound patterns produced in speech are unique
Optional Services (continued)
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Crime-Scene Investigation Unit
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Dispatched specially trained personnel to a crime scene to
collect/preserve evidence to be analyzed later in the lab
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Forensic Psychiatry
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Examines the relationship between human behavior and legal
proceedings
Behavior patterns of criminals/behavior profile
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ID victims based on dental evidence
Bite mark analysis linked to tooth structure on a suspect
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Failure analysis, accident reconstruction, causes/origins of
fires/explosions
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Includes forensic pathology, entomology and anthropology
Forensic Odontology
Forensic Engineering
Forensic Computer/Digital Analysis
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Identifying, collecting, preserving and examining information
derived from computers/digital devices
Key Points:
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The development of crime labs in the USA has been characterized
by rapid growth accompanied by a lack of national and regional
planning and coordination
Four major reasons for the increase in the number of crime labs in
the USA since the 1960s are as follows:
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The fact that the requirement to advise criminal suspects of their
constitutional rights, right to immediate access to counsel has all but
eliminated confessions as a routine investigative tool;
The staggering increase in crime rates in the USA
The fact that all illicit drug seizures must be sent to a lab for confirmatory
chemical analysis before a case can go to court;
The advent of DNA profiling
The technical support provided by crime labs can be assigned to 5
basic services:
Some crime labs offer optional services such as toxicology,
fingerprint analysis, polygraph administration, voiceprint analysis,
and crime-scene investigation.
Special forensic services available to the law enforcement
community include forensic pathology, entomology, psychiatry,
odontology, engineering, computer/digital analysis.
Functions of the Forensic Scientist
 Analyzing Physical Evidence
 Apply principles of physical/natural
sciences in analyzing evidence
 Only physical evidence is free of
error/bias
 Must undergo scientific inquiry – the
integrity of evidence comes from
applying the scientific method
 Not tainted by human error/distortion
of facts
Functions of the Forensic Scientist (continued)
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Determining the admissibility of evidence
 Frye vs. The United States
 Procedures/techniques/principles are
“generally accepted” by the scientific
community
 Federal Rules of Evidence
 Governs admissibility of evidence including
expert testimony on a scientific/technical
matter if:
1. Testimony is based on sufficient facts/data
2. Testimony is the product of reliable
principles/methods
3. Witness has applied the principles/methods
reliably to the facts of the case
(also used in state courts)
Functions of the Forensic Scientist (continued)
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Judging Scientific Evidence
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Judge assumes ultimate responsibility for
admissibility/reliability of evidence
The Court offers some guidelines
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Whether the scientific technique/theory can be tested
Whether the scientific technique/theory has been subject of
peer review/publication
Technique’s potential rate of error
Existence/maintenance of standards controlling the technique’s
operation
Whether the scientific technique/method has attracted
widespread acceptance within the relevant scientific community
Providing Expert Testimony
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Performing the analysis of evidence
May be required to testify in court about their methods, etc.
Education/training is very important
Key Points:
 A forensic scientist must be skilled in applying
the principles and techniques of the
physical/natural sciences to analyzing evidence
that may be recovered during a criminal
investigation.
 The cases Frye vs. the United States and
Daubert vs. Merrell Dow Pharmaceuticals, Inc.
set guidelines for determining the admissibility
of scientific evidence into the courtroom.
 An expert witness evaluates evidence based on
specialized training/experience.
 Forensic scientists participate in training law
enforcement personnel in the proper
recognition, collection and preservation of
physical evidence.