Crime Scene Investigation

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Crime Scene Investigation
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Crime Scene Investigation

• Defining the Crime Scene

• Information Obtained from a Crime Scene

• Processing the Crime Scene

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Crime Scene Investigation

• Defining the Crime Scene

• Information Obtained from a Crime Scene

• Processing the Crime Scene

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Defining the Crime Scene
Where is the crime scene?

• Can be classified by
• Location of Criminal Activity
• Size of Area
• Type of Crime Committed
• Physical Location of the Crime

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Defining the Crime Scene

• Location of Criminal Activity

• Primary where the original crime occurred

• Secondary subsequent crime scenes

Lets look at an example
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Primary vs. Secondary
Tom Bosley
Scott Baio
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Primary vs. Secondary
Tom Bosley
Primary Crime Scene
Scott Baio
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Primary vs. Secondary
Tom Bosley
Secondary Crime Scene
Scott Baio
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Defining the Crime Scene

• Size of Crime Scene

• Macroscopic one location, composed of many
  microscopic crime scenes
• Microscopic focuses on specific type of
  physical evidence

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Macroscopic vs. Microscopic
Tom Bosley
Macroscopic McDonalds Area
(Tom Bosleys body, Chachi, the dumpster, etc.)
Scott Baio
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Macroscopic vs. Microscopic
GSR on Baios hand
Tom Bosley
Microscopic
Scott Baio
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Macroscopic vs. Microscopic
Tom Bosleys Leg Wound
Tom Bosley
Microscopic
Scott Baio
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Defining the Crime Scene

• Type of Crime Committed
• Homicide, Robbery, Sexual Assault, etc.

• Physical Location of Crime Scene
• Indoors, Outdoors, Vehicle, etc.

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Crime Scene Investigation

• Defining the Crime Scene

• Information Obtained from a Crime Scene

• Processing the Crime Scene

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Info from Scene

• Corpus Delicti - the body of the offense
• Must be proven a crime has been committed (i.e.
  dead body should be produced in murder trial)

• Modus Operandi (MO) a certain criminals
  repeated behavior.

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Info from Scene

• Linkage of persons, places and things
• Locard Exchange Principle when two objects come
  into contact with one another, an exchange of
  matter takes place.
• Physical evidence can link suspect, victim, crime
  scene, and objects to one another

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Info from Scene
Suspect
Victim
Object
Crime Scene
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Info from Scene
All found at scene
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Info from Scene
Bullet in Bosley
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Info from Scene
Fingerprints on gun
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Info from Scene
Baios Hair on Bosley
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Info from Scene
Baios suspenders button In dumpster
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Info from Scene

• Proving or disproving witness statements
• Can identify intentional lies
• Can identify unintentional eyewitness
  mistakes

• Identification of Suspects
• Fingerprints and DNA

• Identification of Unknown Substances
• Illegal drugs, poison, anthrax

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Info from Scene

• Corpus Delicti
• Modus Operendi
• Linking people, objects, crime scene
• Proving witness/suspect statements
• Identification of suspects
• Identification of unknown substances
• Providing investigative leads

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Info from Scene

• Corpus Delicti
• Modus Operendi
• Linking people, objects, crime scene
• Proving witness/suspect statements
• Identification of suspects
• Identification of unknown substances
• Proving investigative leads

Reconstruction of Crime
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Crime Scene Investigation

• Defining the Crime Scene

• Information Obtained from a Crime Scene

• Processing the Crime Scene

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Processing the Crime Scene

• Crime Scene Investigation Models
• Requires teamwork by crime scene personnel and
  investigators
• See figure 8.1 in text
• the individual processing the scene depends on
  the state/community

• Detectives
• Patrol Officer
• Crime squad

• Lab Scientist
• Medical Examiner
• Crime scene tech.

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Processing the Crime Scene

1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence

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Processing the Crime Scene

1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence

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First Officer on the Scene

• Safety is the primary concern

• Assist the victim
• Search for and arrest suspect
• Detain and separate witnesses
• Protect the crime scene (barrier tape)
• Note any changes made to the scene

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Processing the Crime Scene

1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence

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Securing the Crime Scene

• Anyone entering the crime scene will deposit and
  remove evidence. (Locard Exchange Principle)

• Secure the scene with physical barriers
• One officer assigned to prevent entrance of
  unwanted personnel
• Log kept of disturbances to scene

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Processing the Crime Scene

1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence

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Crime Scene Survey

• After the scene is secure, the investigator and
  first responder do a walk-through

• Prepare an initial reconstruction
• Note any temporary evidence
• Note points of entry/exit that require attention
• Access scene for personnel, precautions, and
  equipment needed

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Processing the Crime Scene

1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence

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Crime Scene Documentation

• Taking notes
• Videotaping
• Photographing
• Sketching

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Crime Scene Documentation

• Taking Notes of the Crime Scene

• Record activities including
• Notification of personnel
• Arrival Information
• Scene Description (environment, evidence)
• Victim Description

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Crime Scene Documentation

• Videotaping the Crime Scene

• Introduce with case , date, location
• Begin with surroundings (include entrance/exits)
  
• Tape Evidence (wide angle, close-up)
• Victims viewpoint

DO NOT

• Narrate the video or discuss contents
• Edit original video

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Crime Scene Documentation

• Photographing the Crime Scene

• Take examination quality photographs (used
  by experts to interpret evidence)
• Every photo should be recorded in a log
• Take with and without a scale

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Crime Scene Documentation

• Sketching the Crime Scene

• Goal is to record exact position of all evidence
  to aid in reconstruction.
• Rough sketches can be refined into final
  sketches
• Three techniques of measurement are used

X
Y
X
Y
X
Y
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e
e
e
Triangulation
Baseline
Polar Coordinates
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Processing the Crime Scene

1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence

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Searching the Crime Scene

• After scene documentation, a more thorough search
  of the scene is completed
• See table 8.3 for types of search
• Systematic search ensures no piece of physical
  evidence is missed

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Processing the Crime Scene

1. First Officer on the Scene
2. Securing the Crime Scene
3. Crime Scene Survey
4. Crime Scene Documentation
5. Searching the Crime Scene
6. Collection of Physical Evidence

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Collection of Physical Evidence

• One individual designated as evidence collector
• Temporary, fragile, or easily lost evidence
  should be collected first
• Evidence placed in primary and secondary
  containers

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Collection of Physical Evidence

• Liquid or volatile evidence placed in airtight
  containers
• Biological evidence placed in non-airtight
  container and allowed to dry
• Each item packaged separately

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Crime Scene Investigation

• Processing the Crime Scene

• Lab Analysis of Evidence

After the crime scene is processed and the
evidence is analyzed,
Crime Scene Reconstruction can begin
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Crime Scene Reconstruction

• Initial evidence leads to the formation of
  Hypotheses (guesses as to what happened)

Hypotheses are tested by additional analyses
Disproved hypotheses are thrown out, leaving a
reconstruction theory
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Case Study Homicide Scene
Crime Scene
Victim
Suspects