Transcript Introduction To Forensics ppt

An Introduction
to
Forensic
Science
Chapter 1: Lesson 1
Mr. Piskadlo
Westwood High School
What is Forensic Science?
 …the
 Using
application of science to law!
scientific principles to supply
accurate and objective information
reflecting the events that occurred at a
crime.
Forensic Science is…
 Applied
Science
 Often called “criminalistics”
Forensic Science applies
 Chemistry
 Biology
 Physics
 Geology
}
to civil and criminal law
Places physical evidence into a professional
discipline.
The History of
Forensics
Sir Arthur Conan Doyle
 Popularized
physical detection methods
in a crime scene
 Developed the character Sherlock
Holmes
Sir Arthur Conan Doyle

1887 published first novel, A Study in Scarlet

"I've found it! I've found it," he shouted to my companion, running towards
us with a test-tube in his hand. "I have found a re-agent which is
precipitated by haemoglobin, and by nothing else . . . . Why, man, it is the
most practical medico-legal discovery for years. Don't you see that it gives
us an infallible test for blood stains? . . . . The old guaiacum test was very
clumsy and uncertain. So is the microscopic examination for blood
corpuscles. The latter is valueless if the stains are a few hours old. Now, this
appears to act as well whether the blood is old or new. Had this test been
invented, there are hundreds of men now walking the earth who would
long ago have paid the penalty of their crimes. . . . Criminal cases are
continually hinging upon that one point. A man is suspected of a crime
months perhaps after it has been committed. His linen or clothes are
examined and brownish stains discovered upon them. Are they blood
stains, or mud stains, or rust stains, or fruit stains, or what are they? That is a
question which has puzzled many an expert, and why? Because there was
no reliable test. Now we have the Sherlock Holmes's test, and there will no
longer be any difficulty."
Mathieu Orfila (1787 – 1853)
 Father
 1814
of Forensic Toxicology
- Treatise on detection of poisons
& their effects on animals.
Alphonse Bertillon (1853 – 1914)
 Father
of Criminal Detection
 Devised the first scientific system of
personal identification, using body
measurements known as anthropometry
in 1879.
Francis Galton (1822 – 1911)
 Conducted
the first definitive study of
fingerprints and their classification.
 1892
– Treatise entitled Finger Prints
Leone Lattes (1887 – 1954)
 Devised
a simple procedure for
determining the blood type (A,B,O,AB) of
a dried bloodstain
Calvin Goddard (1891 – 1955)
 Used
a comparison microscope to determine if a
bullet was fired from a specific gun
 Published
study of “tool marks” on bullets
Albert S. Osborn (1858 – 1946)
 Developed
fundamental principles of
document examination

1910 – Treatise Questioned Documents
 Was
responsible for the acceptance of
documents as scientific evidence by the
courts
Edmond Locard (1877 – 1966)
 Locard's
Exchange Principle
states that once contact is
made between two surfaces a
transfer of material(s) will occur.
Organization of
a
Crime
Laboratory
Crime Labs
 Since
the 1960's the number of crime labs
increased due to the courts demanding
secure scientifically evaluated evidence.




More crime
More drug related crime
Greater need for physical evidence
Use of DNA profiling (1990’s)
Services of the Crime Lab

Many local crime laboratories have been
created solely for the purpose of processing
evidence

Currently most of their energy and funds are used
to analyze drugs and DNA.

In 1932, Hoover first established a national
forensics laboratory to support all law
enforcement in the U.S.

The oldest American forensics laboratory is in
Los Angeles, California, created in 1923 by
August Volmer.
Crime Lab Units
Standard
Optional
Physical Science
Biology
Firearms
Documents
Photography
Toxicology
Fingerprints
Polygraph
Voice Print
Evidence
Basic Services Provided by
Full-Service Crime Laboratories
 Physical
 Applies
Science Unit:
the principles and techniques of
Chemistry
Physics
Geology
to the identification and comparison of crimescene evidence
 Biology
Unit:
 Identifies
dried bloodstains and body fluids
 Compares hairs and fibers
 Identifes and compares botanical materials such
as wood and plants
 Performs DNA analysis
Basic Services
 Firearms
 Firearms
(continued)
Unit: examines
 Discharged
bullets
 Cartridge cases
 Shotgun shells
 Ammunition of all types
 Document
 Analyzes
Examination Unit:
handwriting, paper and printers of
documents
 Photography
 Examines
Unit:
and records physical evidence at the
crime scene and at suspects' locations
Optional Services Provided by FullService Crime Labs
 Toxicology
 Examines
Unit:
body fluids and organs in order to
determine the presence and identification of
drugs and poisons
 Latent
Fingerprint Unit:
 Processes
and examines evidence for latent
fingerprints
 i.e. those found on surfaces
 Polygraph
 Uses
Unit:
lie detectors, an essential tool of the crime
investigator rather than the forensic scientist
Optional Services (continued)
 Voiceprint


Analysis Unit:
Involved in cases of telephone threats or
tape-recorded messages
Investigators may be able to connect a
voice to a particular suspect
 Evidence-Collection

Unit:
Incorporates evidence collection into a
total forensic science service
The Functions of the
Forensic Scientist
 Analysis

The forensic scientist must be skilled in applying
the principles and techniques of the physical
and natural sciences in order to identify the
many types of evidence that may be
recovered during crime investigations.
 Expert

of Physical Evidence
witness
An expert witness possesses a particular skill or
has knowledge in a trade or profession that will
aid the court in determining the truth.
The Functions of the
Forensic Scientist
(continued)
 Specially
□
trained evidence collection technicians
Training in Proper Recognition,
Collection, and Preservation of
Evidence is required so that
the forensic pathologist, as the
medical examiner or coroner,
can determine the cause of
death via an autopsy.
Other Forensic Services
Forensic Pathology

The cause of death can often be
determined by performing an
autopsy
Other Forensic Services
 Forensic


Anthropology:
Primarily involves the identification and
examination of skeletal remains, in order to
determine if the remains are human or
another type of animal.
If human, ethnicity, sex, approximate age,
and manner of death can often be
determined by an anthropologist.
Other Forensic Services
 Forensic


Entomology
The study of insects and their
developmental stages
Can help to determine the time of death
by knowing when those stages normally
appear in the insect's life cycle
Other Forensic Services - 5
 Forensic



Psychiatry
The study of human behavior and legal
proceedings in both civil and criminal cases
In civil and criminal cases, competency
often needs to be determined
In criminal trials, the evaluation of behavior
disorders is often required in order to
establish the psychological profile of a
suspect.
Other Forensic Services
 Forensic


An odontologist can match bite marks to a
suspect's teeth, or match a victim to his
dental x-rays
Results in an identification of an unknown
individual
 Forensic

Odontology
Engineering
Used to analyze construction accidents,
and the causes and origins of fires or
explosions
Forensic Analysis
 Can
include organic and inorganic
analytical techniques

Organic analysis of unknown substances
 Includes
analytical techniques such as
Chromatography, UV- visible and infrared
Spectrophotometry and Mass Spectrometry.

Inorganic analysis
 Includes
techniques such as the emission
spectrum of elements, Atomic Absorption
Spectrophotometry, Neutron Activation
Analysis, and X-Ray Diffraction Analysis.