Applied Science Often called criminalistics Forensic

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An Introduction toForensic Science

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What is Forensic Science?

• the application of science to those criminal and
  civil laws that are enforced by police agencies
  in a criminal justice system.

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Forensic Science is

• Applied Science
• Often called criminalistics

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Forensic Science applies

• Chemistry
• Biology
• Physics
• Geology
• Places physical evidence into a professional
  discipline.

to civil and criminal law
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The development ofForensic Science
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Sir Arthur Conan Doyle

• Popularized physical detection
  methods in a crime scene
• Developed the character Sherlock Holmes

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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."

? had a considerable influence on popularizing
scientific crime-detection methods
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Mathieu Orfila (1787 1853)

• Father of Forensic Toxicology
• 1814 - Treatise on detection of poisons
  their effects on animals.

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Alphonse Bertillon (1853 1914)

• Father of Criminal Detection
• Devised the first scientific system
  of personal identification, using
  body measurements known as anthropometry in 1879.

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Francis Galton (1822 1911)

• Conducted the first definitive study of
  fingerprints and their classification.
• 1892 Treatise entitled Finger Prints

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Leone Lattes (1887 1954)

• Devised a simple procedure for determining the
  blood type (A,B,O,AB) of a dried bloodstain

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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

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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

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Edmond Locard (1877 1966)

• Demonstrated how the principles developed by Hans
  Gross could be incorporated into a workable crime
  lab.
• Locard's exchange principle states that once
  contact is made between two surfaces a transfer
  of material(s) will occur.

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Organization of aCrime Laboratory
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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 (1990s)

Presently there are 350 Crime Laboratories in the
U.S.
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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.

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Crime Lab Units

• Standard
• Physical Science
• Biology
• Firearms
• Documents
• Photography

Optional Toxicology Fingerprints Polygraph Voice
Print Evidence
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Basic Services Provided byFull-Service Crime
Laboratories

• Physical Science Unit
• Applies the principles and techniques of
  Chemistry
• Physics
• Geology
• to the identification and comparison of
  crime-scene 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

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Basic Services (continued)

• Firearms Unit examines
• Firearms
• Discharged bullets
• Cartridge cases
• Shotgun shells
• Ammunition of all types
• Document Examination Unit
• Analyzes handwriting, paper and printers of
  documents
• Photography Unit
• Examines and records physical evidence at the
  crime scene and at suspects' locations

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Optional Services Provided by Full-Service Crime
Labs

• Toxicology Unit
• Examines 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 Unit
• Uses lie detectors, an essential tool of the
  crime investigator rather than the forensic
  scientist

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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

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The Functions of theForensic Scientist

• Analysis of Physical Evidence
• 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 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.

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The Functions of theForensic 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.

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Other Forensic Services

• Death can be classified into five different
  categories natural death, homicide, suicide,
  accident or undetermined manner of death.
• Forensic Pathology
• The cause of death
  can often be
  determined by
  performing an
  autopsy

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Other Forensic Services - 2

• Forensic Pathology continued
• After a human body expires there are several
  stages of death
• Rigor Mortis
• immediately following death, the muscles relax
  and then become rigid, shortening of the muscles.
• Livor Mortis
• when the human heart stops pumping, due to the
  blood begins to settle in the parts of the body
  closest to the ground due to gravity. The skin
  will appear dark blue or purple in these lower
  areas close to the ground.
• Algor Mortis
• the process in which the body temperature
  continually cools after death until it reaches
  room temperature, enabling the medical examiner
  to establish the general time of death.

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Other Forensic Services - 3

• 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.

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Other Forensic Services - 4

• 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

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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.

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Other Forensic Services - 6

• Forensic Odontology
• 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 Engineering
• Used to analyze construction accidents, and the
  causes and origins of fires or explosions

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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.