Download Forensic Science Introduction Unit I

Forensic Science Introduction
Unit I
• Forensic Science by definition is the application of
science to criminal and civil laws that are enforced by
a criminal justice system.
– 1. our gov’t regulates many activities- quality of
food, nature of drugs, pollution emissions, H2O,
pesticides.
– 2. science occupies an important role in our judicial
system.
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Forensic science- Unit I
• History and the Development of Forensic
Science: Important Figures in History– Sir Arthur Conan Doyle- developed the
fictional character- Sherlock Holmes. Applied
the newly developing principles of serology,
fingerprinting, firearm identification, and
– and questioned-documentation long before their
value was first recognized and accepted by reallife criminal investigators.
– Mathieu Orfila- (1787-1853) “Father of
Toxicology”- published works on the detection
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of poisons and their effects on animals.
Forensic Science Unit I
– Alphonse Bertillon- (1853-1914) developed
science of anthropometry, a systematic
procedure of taking body measurements as a
means of identifying one person from another.
– Francis Galton- (1822-1911) first definitive
study of fingerprints and developed a way of
classifying them.
– Leone Lattes- (1887-1954) Devised a
procedure for determining the blood group of a
dried blood stain.
– Calvin Goddard- (1891-1955) Devised the
comparison microscope used to determine
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Forensic Science- Unit I
– whether a particular gun has fired a bullet. The
comparison microscope allows firearms
examiners to compare the bullet with one that
has been shot from a suspect’s weapon.
– Albert S. Osborn- (1858-1946) Developed
fundamental principles of document
examination which led to documents as
scientific evidence being accepted by the courts.
– Walter C. McCrone- (1916-2002) applied
microscopy to analytical problems, particularly
forensic sciences cases.
– Edmond Locard- (1877-1966)- believed that
when a criminal came in contact with an object 4
Forensic Science- Unit I
– or person, a cross-transfer of evidence occurred.
(Locard’s Exchange Principle) He believed
that every criminal could be connected to a
crime by dust particles carried from the crime
scene.
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Important Services in a Forensics
Crime Lab
• In 1932 the FBI was organized. Its aim was to
offer forensic services to all law enforcement
agencies. It is the largest lab in the world.
• There are 4 major government crime labs:
•
1. FBI
•
2. US Postal Service
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3. Drug Enforcement Admin. Lab
•
4. Bureau of Alcohol, Tobacco, Firearms
and explosives
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Forensic Science - Unit I
– Physical Science Unit-criminalists use chemical
tests and modern analytical instrumentation for
the examination of drugs for drug
identification,glass, paint, explosives, and mineral
analysis for soil identification.
– Biology Unit- biologists and biochemists identify
and DNA profile dried blood stains and other
body fluids, compare hairs and fibers, and
identify and compare botanical items such as
wood or plants.
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Forensic Science Unit I
– Firearms Unit- examination of firearms,
discharged bullets, cartridge cases,, shotgun
shells, and ammunition of all types. Garments and
other objects are also examined in order to detect
firearm discharge residues and to approximate the
distance from a target at which a weapon was
fired.
– Documentation Examination Unit- Authenticity
and/or source of handwriting or typewriting on
questioned documents is examined.
• Analysis of paper, ink, indented writings, erasures,
burned or charred writing invisible to the eye.
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– Photography Unit- used to examine and record
physical evidence and to prepare photographic
exhibits for courtroom presentations.
• Digital imaging- use of infrared, x-ray, UV to make
info. Visible to the eye.
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• Services of the Crime Lab: Optional
Services
Forensic Science- Unit I
– Toxicology Unit- Body fluids and organs are
examined to determine the presence or absence of
drugs or poisons.
– Latent Fingerprint Unit- processes and
examines evidence for latent fingerprints.
• Left at the scene, not imprinted.
– Polygraph Unit- Lie detector
– Voiceprint Analysis Unit- With telephone
threats or taped messages, voiceprint analysis can
tie the voice to a particular suspect.
– Evidence-Collection Unit- Coll., preserves evid.
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Forensic Science- Unit I
• Functions of Personnel Involved in
Criminology
– Forensic Scientist- must effectively analyze
many types of evidence during a criminal
investigation, while being aware of the demands
and constraints of the judicial system. May be
required to testify as an expert witness.
• Procedures and techniques must satisfy the criteria of
admissibility set by courts- very specific.
• Must demonstrate ability and competence in court.
• Sometimes an opinion based on experience.
• CSI- gather evidence at crime scene.
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• Police- Every officer engaged in field work (traffic, petrol,
investigation or juvenile control) will often have to collect
and process evidence for laboratory examination. Training
police for this task is very important.
• Forensic Pathology- in their role as a medical examiner, or
coroner, forensic pathologists need to determine the injuries
present, when, how, and why were the injuries produced, and
what was the cause of death. Autopsies are often performed
to establish the cause of death.
– Death is deemed suspicious or unexplained. Ex.- gun in
hand and shotgun wound- suicide? Murder? Could be
toxicological or suffocation.
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• Time of Death
– Livor mortis- pooling of blood in areas
closest to the ground
– Algor mortis- rate at which the body
loses heat. 1-11/2º F per hour until environ. temp.
– Rigor mortis– manifests in 24 hours.
• Shortening of muscle tissue- stiffness
• Disappears after about 36 hours.
Pine plains
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Forensic Science- Unit I
– Forensic Anthropology- concerned primarily
with the identification and examination of human
skeletal remains.
• Identify gender, race, age
• Bones are durable, slow decomposition
– Facial reconstructions
– Forensic Entomology- The study of insects and
their relation to a criminal investigation. Time of
death can often be determined by studying what
insects inhabit the body and by determining the
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Forensic Science- Unit I
– development stage of the insect.
– Blowflies are the first to inhabit a dead bodyeggs are laid and larva emerge- larva eat remains.
– Forensic Psychiatry- evaluate behavioral
disorders and determine whether people are
competent to stand trial. Also examine behavioral
patterns of criminals as an aid in developing a
suspect’s behavioral profile.
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– Forensic Odontology- study the characteristics
of teeth, their alignment, and the overall structure
of the mouth to provide evidence for identifying a
specific person. Also perform bite mark analysis.
• Teeth are the hardest part of the body. Compare dental
records to suspected victim’s dental records.
– Forensic Engineering- concerned with failure
analysis, accident reconstruction, and causes and
origins of fires or explosions.
» CSI Effect
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wildlife forensic science
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