What exactly is Forensic Science?

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INTRODUCTION

• Chapter 1

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What exactly is Forensic Science?

• Forensic science applies the knowledge and
  technology of science to define and enforce laws.

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The History of Forensics

• Mathieu Orfila (Spain)
• Father of Forensic Science(1787-1853)
• Established the science of Forensic Toxicology,
  by studying the effects of toxins on animals
• Alphonse Bertillon (France) (1853-1914)
• Developed the science of Anthropometry a way of
  taking extensive body measurements to identify
  people. This technique of personal identification
  was considered extremely accurate for 2 decades
  and was eventually replaced by fingerprinting.

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More important people!

• Francis Galton (1822-1911)
• Proved the uniqueness of human fingerprints and
  published a book called Finger Prints. Current
  fingerprinting techniques are based on his
  research.
• Leone Lattes (1887-1954)
• Devised a technique to determine the blood group
  of a dried bloodstain and applied the technique
  to criminal investigations. (The ABO blood
  groups were discovered by a Dr. Karl Landsteiner
  in 1901)

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And more

• Calvin Goddard (1891-1955)
• Used microscopy to determine if a bullet was
  fired from a particular gun, and if that compares
  to the suspects weapon and a crime scene bullet.
  Modern firearms examiners still use his
  techniques.
• Albert S. Osborne (1858-1946)
• Published a book Questioned Documents, and was
  responsible for the acceptance of documents as
  scientific evidence by courts. Modern document
  examiners still use his book as primary refernce.

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A couple more

• Walter C. McCrone (1916-2002)
• Did extensive work with microscopy to examine
  forensic evidence.
• Hans Gross (1847-1915)
• The first person to write about marrying all arms
  of science (Botany, antropology, chemistry,
  physics, mineralogy, etc.) into one unified
  investigative science Forensics.

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Last but not least

• Edmond Locard (1877-1966)
• Established Locards Exchange Principle which
  state that, whenever 2 objects come in contact
  with each other, there will be an exchange of
  materials between the two.
• Therefore, when a criminal comes in contact with
  an object or a person, a cross-transfer of
  evidence occurs. So you can find something of
  the criminal on the victim and vice versa.

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• In 1932, thanks to J. Edgar Hoover, the director
  of the FBI, launched a national lab that would
  offer forensic services to the entire countrys
  law enforcement agencies.
• Today, the FBI laboratory is the largest and most
  reputable in the world.

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Basic Services of a Full-Service Crime Lab

• Physical Science Unit
• Biology Unit
• Firearms Unit
• Document Examination
• Photography Unit

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Optional Services of a Full-Service Crime Lab

• Toxicology Unit
• Latent Fingerprint Unit
• Polygraph Unit
• Voiceprint Analysis Unit
• Evidence-Collection Unit

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Specialized Forensic Services

• These are provided by specialized individuals,
  and are not usually a part of a full-service
  crime lab.
• Forensic Pathology
• Forensic Anthropology
• Forensic Entomology
• Forensic Psychiatry
• Forensic Odontology
• Forensic Engineering

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1.Forensic Pathology

• Investigates sudden, unnatural, unexplained, or
  violent deaths. Questions a forensic pathologist
  must attempt to answer
• - Who is the victim?
• - What injuries are present?
• - When did the injuries occur?
• - What caused the injuries?
• - What was the time of death?
• http//www.pathguy.com/TimeDead.htm
• If a cause of death cannot be determined by
  external observation of the body, then an Autopsy
  is required.

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Autopsy (means to see for oneself)

• This a medical dissection of a body to determine
  cause of death. Causes of death can be classified
  as
• - Suicide
• - Homicide
• - Accident
• - Natural causes
• - Undetermined

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Autopsy contd.

• The early stages of decomposition after death
  involve
• Rigor mortis the muscles first relax, then
  stiffen. The body becomes rigid. Rigor mortis
  occurs within 24 hours after death and terminates
  within 36 hours.
• Livor mortis Once the heart stops pumping, the
  blood tends to pool in the parts of the body
  closest to the ground due to gravity. The skin in
  these areas appear purplish. However, skin that
  was restricted by belts, etc. will not appear
  purplish. This can help determine if the body
  was moved after death. Livor mortis begins
  immediately after death and continues for up to
  12 hours.

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Rigor Mortis
Livor Mortis
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Autopsy contd.

• Algor mortis this is the conditions where the
  body temperature cools and reaches the ambient or
  room temperature. The location, size of body,
  clothing, weather conditions, etc. all play a
  role in algor mortis.
• Generally speaking, beginning an hour after
  death, the body loses heat at the rate of 1 or
  1.5 degrees Fahrenheit per hour until body
  reaches ambient temperature.

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Pallor Mortis
Pallor mortis (paleness of death) is a postmortem
paleness which happens almost instantaneously (in
the 15120 minutes after the death) because of a
lack of capillary circulation throughout the
body. Paleness develops so rapidly after death
that it has little to no use in determining the
time of death.
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Other Autopsy Factors

• Potassium levels in vitreous humor of eye after
  death, cells of the inner eye release potassium
  into the ocular fluid called vitreous humor.
  Examining these levels help determine time of
  death.
• Amount of food in stomach can help determine
  when last meal was eaten.

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How long does food take in the GI tract?
50 of stomach contents emptied 2.5 to 3 hours
Total emptying of the stomach 4 to 5 hours
50 emptying of the small intestine 2.5 to 3 hours
Transit through the colon 30 to 40 hours
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2. Forensic Anthropology

• Deals with identification and examination of
  human skeletal remains. Bones degrade at an
  incredibly slow rate. They can tell
• - Sex
• - Age
• - Race / Origin
• - Type of injury (cause of death?)
• Forensic anthropologists are often needed to
  identify victims of a mass disaster such as air
  crashes, 9/11 WTC disaster, bombings, etc.

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Ways to tell male pelvis from female
spread of ilium female more flared and
cradle-like with anterior iliac spines farther
apart vs. more straight up-and-down in male
shape of hole in ischium smaller and triangular
in female vs. larger and rounded in male angle
across pubic symphysis pubic arch less than 90
(acute angle) and more sharply angled in male,
greater than 90 (obtuse angle) and more rounded
in female inner diameter and distance between
ischia larger in female--big enough for head of
baby to pass through
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• Sometimes forensic anthropologists have to use
  Facial Reconstruction artists to help identify
  the remains.

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http//www.crimelibrary.com/criminal_mind/forensic
s/art/5.html
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3. Forensic Entomology

• The study of insects and their relationship to a
  criminal investigation. Can help determine time
  of death.
• After death, specific insects become inhabitants
  of the corpse in a specific sequence. Blowflies
  are usually the first to arrive. Knowing the
  life cycles and studying the maggots can help
  determine time of death. Ambient temperatures
  can play a role in insect life cycles, so it can
  be tricky to rely solely on this method.

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A Blowfly and its maggots
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4. Forensic Psychiatry

• The relationship between human behavior and legal
  proceedings is examined. Forensic psychiatry can
  help determine
• - If a person is fit to stand trial
• - Suspects behavioral profile
• - Behavioral patterns of criminals (Profiling)

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Susan Smith
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5. Forensic Odontology

• Using teeth to identify remains. Tooth enamel is
  the hardest substance in the body and usually the
  last to decompose. So teeth can be used (and old
  dental records such as X-rays and casts) to
  identify a body in an unrecognizable condition.

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Dental Impressions and Casts
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6. Forensic Engineering

• This aspect of forensic science includes accident
  reconstruction, causes and origins of fires and
  explosions.

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Body Mystery

• http//americasunknownchild.net/Medical.html
• www.crimelibrary.com

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THE END