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Chapter 1 Introduction
Section 1-4 Training for Physical Evidence and
Other Forensic Services
I will be able to:
• Describe training of law enforcement
• Describe other forensic services available to law
enforcement
Why it’s important:
Law enforcement need to know the proper
recognition, collection, and preservation of physical
evidence and other available forensic services
Training in the Proper Recognition, Collection, and
Preservation of Physical Evidence
• Competence of lab
staff and
sophistication of
analytical equipment
useless if evidence not
properly recognized,
collected, and
preserved
• Evidence-collection
Technicians – specially
trained at crime scene
Training in the Proper Recognition, Collection, and
Preservation of Physical Evidence
Evidence technicians
must:
• Recognize and gather
pertinent physical
evidence at the crime
scene
• Be assigned to the lab
to facilitate their
continued exposure to
techniques and
procedures
Training in the Proper Recognition, Collection, and
Preservation of Physical Evidence
• Have the proper tools
and supplies available
for examination
• Include all police
officers engaged in
field work
Other Forensic Science Services
Forensic Pathology:
• Investigation of
sudden, unnatural,
unexplained, or violent
deaths
• Determine cause of
death
• Forensic pathologists
– Who is victim?
– What injuries
present?
– When injuries
occur?
– Why and how
injuries produced?
Forensic Pathology
• Perform autopsies
• Determine manner of
death – natural,
homicide, suicide,
accident,
undetermined
Forensic Pathology
• Estimate the time of
death based on
decomposition
– Rigor mortis 24 – 36 hours
– Liver mortis –
up to 12 hours
– Algor mortis –
1 -1.5 0F per hour
Immediately following
death:
• Muscles relax
• Rigor mortis – muscles
become rigid w/o
shortening of muscle
• Liver mortis – blood
settles in parts of
body closest to ground
– determines position
of body
Forensic Pathology
• Potassium levels in
ocular fluid
• Food levels in stomach
• Algor mortis –
temperature of body
cools after death to
room temperature
- Loses 1 – 1.5 0F per
hour
• After death, cells in
inner surface of eye
ballss release K into
ocular fluid
– Rate of release can
determine time of
death
Other Forensic Services
Forensic Anthropology –
identification and
examination of human
skeletal remains:
• Can identify sex, age,
race, and injury
• Can create facial
reconstructions
• Can collect bone
fragments from mass
disasters and ID (ex:
plane crashes)
• Bones are durable
• Undergo extremely
slow breakdown
process lasting
decades or centuries
• Provide multitude of
individual
characteristics
Other Forensic Services
Forensic Entomology –
study of insects and
their relation to
criminal investigation
• Blow flies – first to
infest the body
• Knowledge of insects,
life cycles, and habits
Other Forensic Services
Forensic Psychiatry –
relationship of human
behavior and legal
proceedings
• Retained for criminal
and civil cases
• Develops behavioral
profiles
• Civil - determine
competency to make
decisions about wills,
settling property,
refusing medical
treatment
• Criminal –evaluate
behavioral disorders
to determine
competency to stand
trial
Other Forensic Services
Forensic Odontology –
use teeth to ID victims
when body is left in
unrecognizable state
• Bite mark analysis
• Use x-rays, alignment,
structure of the
mouth for ID
• Enamel is hardest
substance in body
• Teeth will outlast
tissues and organs as
decomposition begins
Other Forensic Services
Forensic Engineering –
structure failure
analysis, accident
reconstruction, causes
and origins of fires or
explosions
• How did they occur?
• Who was responsible?
• How were they
responsible?
Forensic Engineering
• Accident scenes
examined
• Photographs reviewed
• Any mechanical
objects involved
inspected
In-class Assignment/Homework
1-4 Section Review Questions
End of Chapter 1:
• Case Study: Detection of Curare in the
Jascalevich Murder Trial
• Deductive Reasoning Exercise:
The Deadly Picnic
• Study Guide
• Test