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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
A

D

A

P

T
First Officer at the Scene
Assess the crime scene
Detain the witness
Arrest the perpetrator
Protect the crime scene
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 8

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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Date: August 14, 2001
Time: 11:35
A. Couch/sofa
B. Female body
C. Knife
D. Over turned Lamp
E. Chairs
F. Table
G. Fireplace
Crime Scene
Sketch
Criminalist: Ann Wilson
Location: 4358 Rockledge Dr
St. Louis, Mo.
c
E
D
A
G
E
E
E
F 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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