Transcript FORENSIC SCIENCE - Mount Mansfield Union High School

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 (Review)
 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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Crime Scene Mapping
(outdoors)
Azimuth--uses a compass beam to determine
the location of each piece of evidence
Triangulation--uses two points at the crime
scene to map each piece of evidence
Coordinate or grid--divides the crime scene into
squares for mapping.
Suspended Polar Coordinate--for use in
mapping evidence in a hole
Baseline--set a north/south line and measures
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each piece of evidence from this line.
AZIMUTH
Determines:
•Direction
•Distance
•Elevation
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TRIANGULATION
Measure from A to B
and then to the
evidence in a
triangular shape.
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Coordinate or
Grid Mapping
Set a north/south
line from a datum
point established
by a GPS.
Make it a perfect square (4 x 4)
by shooting the hypotenuse
and setting in stakes every foot
or meter.
Measure and map
the location of each
piece of evidence.
Then collect
evidence and place
in containers by
grid.
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Baseline Mapping
Set a north/south line from
the furthest most points
of the crime scene. Then
measure each piece of
evidence from that
baseline. Evidence will
need a numerical
measurement where the
piece begins, ends and in
the middle.
Evidence
Baseline
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Suspended Polar
Coordinate
Measure and map each
layer of evidence as
you move down the
hole. Use the
compass readings
from the top to
measure degrees and
a tank dipping line to
measure depth.
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MAPPING
TECHNOLOGY
The latest technology
includes this Nikon
Tsunami with computer.
The exact location of all
crime evidence can be
determined and directly
loaded into a computer
to produce a crime scene
map. Cost = $35,000
for the set.
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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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