Transcript Forensic Scientists

Forensic Scientists
Criminalist (CSI)
Analyzes, compares, identifies, & interprets
physical evidence at crime scenes.
Forensic Pathology
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Involves the investigation of sudden,
unnatural, unexplained, or violent deaths.
– Typically these are the medical examiners or
coroners
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Answer questions: who is the victim, what
injuries are present, when did the injuries
occur, why and how were the injuries
produced, and what is the cause of death
Manner of Death
Natural: 80 year old dies of congestive
heart failure
 Homicide: death caused by another
person
 Suicide: death inflicted upon self
 Accidental: unintentional and without
malice, group swimming and one drowns
 Undetermined: absolute cause not able to
be determined
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Cause of Death
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Asphyxiation
– Strangulation
– Drowning
– Fire victim
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Exsanguination
– Major blood loss
Blunt force trauma
 Sharp force trauma
 Chemical trauma
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Estimated Time of Death
Autopsy: medical dissection and
examination of a body in order to
determine the cause of death
 Rigor Mortis: medical condition that occurs
after death and results in the shortening
of muscle tissue and the stiffening of body
parts in the position they are in when
death occurs. Occurs within 24 hours and
gone within 36 hours
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Estimated Time of Death
Livor Mortis or lividity: medical condition
that occurs after death and results in the
settling of blood in areas of the body
closest to the ground. Begins immediately
after death and lasts for 12 hours
 Algor Mortis: postmortem changes that
cause a body to lose heat. Process in
which the body continues to cool to room
temperature. 1 – 1.5 degree/hour
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Evidence to be Collected at Autopsy
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Victim’s clothing
Fingernail scrapings
Head and pubic hairs
Blood (for DNA typing)
Vaginal, anal, and oral swaps (sex-crimes)
Recovered bullets/knives from body
Hand swabs from shooting victims (for GSR
analysis)
Forensic Anthropology

Identification and examination of human
skeletal remains
– Trying to determine origin, sex, approximate
age, race and skeletal injury
– May create facial reconstruction
– Identify victims of mass disaster such as plane
crash
Forensic Entomology

Study of insects and
their relation to a
criminal investigation

After decomposition
begins, insects such
as blow flies are the
first to infest the body
Forensic Psychiatry

Specialized area in which the relationship
between human behavior and legal
proceedings is examined
– Civil cases: determine whether people are
competent to make decisions about wills,
refusing medical treatment, etc.
– Criminal cases: determine whether people are
competent to stand trial
– Develop suspect’s behavior profile
Forensic Odontology
Provide information about the
identification of victims when the body is
left in an unrecognizable state
 Teeth are composed of enamel which is
the hardest substance in the body
 Characteristics of teeth, alignment, and
overall structure of the mouth provide
method for identification
 Also analyze bite marks
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Forensic Engineering

Concerned with:
– Failure analysis
– Accident reconstruction
– Cause and origin of fires or explosions

Answer questions such as how did an
accident occur or what structural failure
occurred
Forensic Nurse
Provides treatment for
crime victims. They are
especially needed in
emergency rooms to
gather and package
criminal evidence.
Forensic Toxicologist
Analyses alcohol, drugs, & poisons in body
fluids for the benefit of the courts.
Defense Wounds #1
Defense wounds on the hand of a victim whose
assailant was attacking with a knife.
Defense Wound #2
Here is a typical "defense wound" on the forearm of
the victim of an assault with a sharp weapon,
producing the laceration.
Defense Posture
Scene illustrates mechanism for "defense wounds".
Clay Model Used to
Demonstrate Knife Wounds
double edge
knife wound
single edge
knife wound
Stab Wound: Single Edge Blade
Sharp edge
of blade
Deadly blow to head that resulted in
fractured skull and bleeding.
Fractured Liver:
Blunt Force Injury
Natural Death:
*Infiltrating Ductal Carcinoma of the Breast
*Pathologist’s
photo of embryo
(ectopic
pregnancy)
Forensic Pathologist’s Tools of
the Trade
More autopsy tools…
Stryker Saw:
good for cutting into skull
Digital Imagery Reconstruction:
Use of computer superimposes photo
of skull with outer skin.
Facial reconstruction technique
used by forensic artists.