FORENSIC
SCIENCE
Crime Scene Analysis
CRITICAL
THINKING
When Mrs. Jackson came
back from lunch, there were
several messages on her desk.
By changing each digit of the
phone numbers to one of the
three corresponding letters on
the telephone buttons, can
you determine from whom
each message came?
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Answers
to Critical Thinking
336-8478
(222)686-8268
774-6837
487-2263
247-5463
832-2437
dentist
accountant
printer
husband
airline
teacher
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FACETS OF GUILT
Means--the ability of have committed the crime
Motive--the reason for committing the crime.
(This doesn’t have to be proven or presented in
a court of law, but its what everyone wants to
know.)
Opportunity--time or availability to have
committed the crime.
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Murder Charges
1st Degree Murder--premeditated
2nd Degree Murder--killed intentionally, but
not thought out as much ahead of time
Voluntary Manslaughter--usually involves
sudden passion (fear, rage, anger, terror)
Involuntary Manslaughter (criminally negligent
homicide)--killed someone, but unintentionally
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Crime Scene Team
Is a group of professional
investigators, each trained in a
variety of special disciplines.
Team Members
 First Police Officer on the scene
 Field Evidence Technician
 Medical Examiner (if necessary)
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First Officer
at the Scene
A
Assess the crime scene
D
Detain the witness
A
Arrest the perpetrator
P
Protect the crime scene
T
Take notes
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Evidence Technician
 Record the crime scene
 Photography
 Sketches
 Notes
 Conduct a search for evidence
 Set up numbers at the pieces of
evidence
 Has the necessary equipment
 Forceps
 Bags--paper and plastic
 Envelopes
 Jars and Q-tips
 Properly collect all evidence
 Maintain a chain of custody
 Obtain reference samples (evidence
whose origin is known)
 Submit evidence to Lab
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Medical Examiner’s
Responsibilities
 Identify the deceased
 Establish the time and date of death
 Determine a medical cause of death--the injury or disease that resulted in
the person dying
 Determine the mechanism of death--the physiological reason that the
person died
 Classify the manner of death





Natural
Accidental
Suicide
Homicide
Undetermined
 Notify the next of kin
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Physical Evidence
All objects that can establish that a crime has
been committed
Can potentially link a crime to a victim and/or a
crime to a perpetrator
Can be anything from massive objects to
microscopic traces
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Evidence
Characteristics
Class Evidence--common to a group of objects or persons
Individual Evidence--can be identified with a particular
person or source.
ABO Blood Typing
Blood DNA Typing
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Crime Scene
Sketch
Date: August 14, 2001
Time: 11:35
Criminalist: Ann Wilson
Location: 4358 Rockledge Dr
St. Louis, Mo.
A. Couch/sofa
E
c
B. Female body
D
C. Knife
D. Over turned Lamp
E. Chairs
E
F. Table
G. Fireplace
G
A
F
E
E
E
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Crime Scene
Search Patterns
TWO of FOUR PATTERNS
Spiral
Grid
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Crime Scene
Search Patterns
TWO of FOUR PATTERNS
Strip or Line
Quadrant or Zone
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TRIANGULATION
Measure from A to B
and then to the
evidence in a
triangular shape.
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Remember:
“HOW PLUS WHY EQUALS WHO”
--John Douglas, former FBI profiler
Keep this in mind as you analyze a crime scene…
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