Download A forensic scientist must be skilled in applying the principles and

Forensic Science
Original Powerpoint Adapted from
Richard Saferstein
Prentice Hall
and Mrs. Partridge LHS
Definition
fe-ren’ sik adj relating to, used in, or
appropriate for courts of law or for
public discussion or argumentation
Latin forensis – public,
of a forum
forensic science is the
application of science
to criminal and civil laws.
Criminalistics
A body of knowledge concerning
the recognition, collection,
identification,
individualization, and
evaluation of physical evidence
using the techniques of
natural science in matters of
legal significance.
What a forensic scientist
DOES!
She deals with life’s
grimmest realities
dispassionately while
never losing sight of
the feelings that keep
her human
What a forensic scientist
DOES
A forensic scientist must be skilled in
applying 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.
 A forensic scientist may also provide
expert court testimony.

Is it “forensics”?
The “science” of forensic science
 Scientific method

Observing Problem
 Researching problem – survey the scene
 Hypothesizing – who committed the crime based on
evidence
 Testing – analyze the evidence to see if it implicates
a suspect
 If answer is wrong, start over
Avoid forming conclusions too early in an investigation.
You may miss/neglect evidence.

Is it “forensics”?

Forensic Process R.I.I.R.
 Recognition

Scene survey, documentation, collection &
preservation
 Identification

Comparison testing
 Individualization

Evaluation, interpretation
 Reconstruction

Reporting & presentation -
Scope of Forensic Science
Criminalistics – the
application of physical
sciences to criminal
investigation
 Specialties
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Medicine
Anthropology
Odontology
Entomology
Legal
Document analysis
Ballistics
Facial reconstruction
others
History of Forensic Science

Many believe that
Sir Arthur Conan
Doyle popularized
scientific crimedetection methods
through his fictional
character Sherlock
Holmes
History of Forensic Science


Holmes applied new, developing
principles of serology, fingerprinting,
firearm ID, and questioneddocument examination long before
their value for first recognized and
accepted by real criminal
investigators
Doyle’s first novel, A Study in
Scarlet, has examples of his ability
to describe scientific methods of
detection, years before they were
actually discovered and implemented
History of Forensic Science
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Forensic Science has been around nearly 900 years
First recorded application of medical knowledge to the solution
of a crime was in 1248
1836 - James Marsh detected arsenic poisoning in connection
with a criminal investigation
1839 - Mathieu Orfila, toxicology, perfected techniques to trace
poisons
1879 - Alphonse Bertillon developed anthropometry, body
measurements to distinguish individuals
Late 1800’s - Alexandre Lacassagne, ballistics and bloodstain
patterns
History of Forensic Science

1892 – Francis Galton developed
methodology of classifying and
filing fingerprints
1901 Karl Landsteiner discovered blood typing
 1915 Leone Lattes devised a
simple procedure for
determining blood group

History of Forensic Science
1910 Edmund Locard, exchange principle,
1st forensic science journal (Locard’s
Exchange Principle—states that when a
criminal comes in contact with an object or
person, a cross-transfer of evidence
occurs)
 1924 August Vollmer, LAPD crime lab (oldest)
 1932 FBI laboratory, fingerprints
 1980’s DNA testing
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()
Forensic Science in the USA
Federal (FBI, DEA,
secret service, ATF)
 State (coroner,
medical examiner)
 Local (sheriffs,
police)
 Private (DNA labs)
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Stop/warn
Coroner vs. Medical Examiner
Coroner – an elected
official with death
investigation duties
 Medical Examiner – an
appointed government
official, always a
physician and often a
forensic pathologist,
with duties of
investigating sudden and
unexpected deaths or
deaths from injuries

Basic Services Provided by Crime
Laboratories
Physical Science Unit (drugs,
glass, paint, soil, explosives)
 Biology Unit (DNA, hairs, fibers,
plants)
 Firearms Unit (ammunition)
 Document Examination Unit
(handwriting, authenticity)
 Photography Unit (all photo;
presentations for court)

Optional Services Provided by
Crime Laboratories
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Toxicology Unit (drugs,
poisons)
Latent Fingerprint Unit
Polygraph Unit
Voiceprint Analysis Unit
Evidence Collection Unit
Envelope containing anthrax spores sent to
Senator Tom Daschle shortly after 9/11. A
variety of forensic skills used to examine it:
Law and Science (see guided notes)
The philosophical foundation of
the criminal justice system
remains to PROTECT the
innocent and to ensure that the
TRUTH EMERGES for any
matter before the court,
thereby ensuring that JUSTICE
IS DONE
Bill of Rights

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The Bill of Rights was
designed to expressly reserve
certain powers to the citizens
against the Federal
Government
The Bill of Rights was not
always understood to apply to
the rights of citizens when
actions involved the state
Precedent Cases
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Mapp v. Ohio, 1961: The
4th Amendment prohibits
unreasonable searches
Robinson v. California,
1962: The 8th Amendment
protects against cruel and
unusual punishment
Gideon v. Wainwright,
1963: The 6th Amendment
provides the right to
counsel
Application of the Bill of
Rights

Amendments 1 through 14 apply to all states,
saying:
The Federal constitution provides
the minimum protection. The state
may provide greater protection but
not less.
()
th
4
Amendment
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The right of the people to be
secure in their persons, houses,
papers and effects against
unreasonable search and
seizures shall NOT be violated
No Warrants shall be issued but
upon probable cause, supported
by an Oath or affirmation,
particularly describing the place
to be searched and the persons
or things to be seized
th
4
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Amendment
The 4th Amendment requires that
a valid warrant be issued prior to
any search
A warrantless search is
Presumptively
Unreasonable!
th
4
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Amendment
A valid warrant is required
for all unreasonable
searches and seizures
Required to obtain a
warrant
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Probable cause
Oath or affirmation
Particular description area to
be searched
What you’re searching for
Evidentiary Information
The probable cause
clause requires that
the police establish
the trust worthiness
of the information
that they base their
observations that a
crime has been
committed.
Two Types of Information
Sources
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Citizen or victim
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Both are generally
trustworthy
No need to collaborate
The informant

Credibility of informant is
important because
informants may also be
involved in criminal activity
themselves
Two Prong Test For An
Informant
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Reliability of information
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Established by identifying how, when, and where
the informant received his information
Credibility of the Informant

Established by identifying the informant,
determining his self-interest, & identifying the
past accuracy of the informant
Warrant Specificity
The following must also be
included on the warrant:
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Place - specific
Time
Items searching for
Neutral authority – judges
permission
Area of Protection
Areas of reasonable
expectation of privacy:
 Car
 Office
 House
Abandoned property does
not require a search
warrant.
Warrantless Entry
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Consent
Plain view
Exigent circumstance
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Fire scene
Belief that a person within is in
need of immediate aid
Cars parked in a public place
Inventory of locked areas
Caretaker
Search incident to custodial
arrest
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Arrestee’s clothing
$5,040.00 In Hidden Compartment
Chain of Custody
Once the items have been
seized and inventoried,
chain of custody must be
fully documented
 Specifies: who seized it,
and every subsequent
individual who has custody
or control of the item
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Packaging of Evidence
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The CSI must make sure that the
evidence is properly packaged
according to the
recommendations of the forensic
laboratory
When evidence is presented in
court, it should be professionally
packaged and presented
It it’s necessary to repackage
evidence, the original packaging
must be included in or securely
attached to the new package
Not like this!
Team Work
Forensic scientists work as members of a larger
team, perhaps other specialized scientists,
law enforcement investigators, prosecutors,
defense attorneys, judges, juries and the
media.
Law and Science

Lawyers have an
OBLIGATION to
conduct a spirited
defense of the accused,
especially if they are
guilty
Law and Science
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In contrast, forensic
science remains
JUSTIFICATION based,
reaching the truth,
dependent upon evidence
and data
All scientists are required
to uphold a high ethical
standard, bound to
combine scientific skills
with a sworn duty to the
public good
Law and Science
From crime scene to conviction, a good forensic
scientist will be teaching others, an ability that
requires patience and the communication of complex
principles in simple terms.
Law and Science
Frye Standard
(named after the 1923 case)
Requires the court to determine
whether the scientific theory
and/or scientific method used
to generate evidence are
generally accepted as reliable in
the scientific community
Law and Science
1.
2.
3.
Frye test:
Is the scientific theory generally accepted
in the scientific community? (experts)
Is the scientific method used generally
accepted in the scientific community?
(papers, books on the subject)
Has the technique been applied correctly?
Law and Science
Daubert v. Merrel Dow
Pharmaceutical, Inc
Trial judges must assume
the ultimate responsibility
for acting as a
‘gatekeeper’ in judging the
admissibility and
reliability of scientific
evidence presented in
their courts
Law and Science
1.
2.
3.
4.
5.
Daubert Ruling Guidelines
Whether the scientific technique/theory can be
(has been) tested
Whether the technique/theory has been subject to
peer review and publication
The technique’s potential rate of error
Existence & maintenance of standards controlling
the techniques operation
Whether the scientific theory /method has
attracted widespread acceptance within a relevant
scientific community
An Expert’s Role
By law, only a judge can
declare someone an expert
witness
 Attorneys offer an expert
witness to the court to
give opinions within their
expertise
 Used to help clarify facts
or educate the jury

Court Advice For a Forensic
Scientist
“Whereof one can not speak, thereof
one must remain silent.”
- Ludwig Wittgenstein