crime scene investigation. defining the crime scene information obtained from a crime scene...
Post on 17-Dec-2015
280 Views
Preview:
TRANSCRIPT
Crime Scene Investigation
Crime Scene Investigation
Defining the Crime Scene
Information Obtained from a Crime Scene
Processing the Crime Scene
Crime Scene Investigation
Defining the Crime Scene
Information Obtained from a Crime Scene
Processing the Crime Scene
Defining the Crime Scene
Can be classified by: Location of Criminal Activity Size of Area Type of Crime Committed Physical Location of the Crime
Where is the crime scene?
Defining the Crime Scene
Location of Criminal Activity
Primary = where the original crime occurred
Let’s look at an example
Secondary = subsequent crime scenes
Primary vs. Secondary
Tom Bosley
Scott Baio
Primary vs. Secondary
Tom Bosley
Scott Baio
Primary Crime Scene
Primary vs. Secondary
Tom Bosley
Scott Baio
Secondary Crime Scene
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
Macroscopic vs. Microscopic
Tom Bosley
Scott Baio
Macroscopic = McDonalds Area(Tom Bosley’s body, Chachi, the dumpster, etc.)
Macroscopic vs. Microscopic
Tom Bosley
Scott Baio
Microscopic
GSR on Baio’s hand
Macroscopic vs. Microscopic
Tom Bosley
Scott BaioMicroscopic
Tom Bosley’s Leg Wound
Defining the Crime Scene
Type of Crime Committed Homicide, Robbery, Sexual Assault, etc.
Physical Location of Crime Scene Indoors, Outdoors, Vehicle, etc.
Crime Scene Investigation
Defining the Crime Scene
Information Obtained from a Crime Scene
Processing the Crime Scene
Info from Scene
Corpus Delicti - the body of the offenseMust be proven a crime has been committed
(i.e. dead body should be produced in murder trial)
Modus Operandi (MO) – a certain criminal’s repeated behavior.
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
Info from Scene
Victim
Object
Suspect
Crime Scene
Info from SceneAll found at scene
Info from SceneBullet in Bosley
Info from SceneFingerprints on gun
Info from SceneBaio’s Hair on Bosley
Info from SceneBaio’s suspenders’ button
In dumpster
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
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
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
Crime Scene Investigation
Defining the Crime Scene
Information Obtained from a Crime Scene
Processing the Crime Scene
Processing the Crime SceneCrime 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.
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
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
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
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
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
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
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
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
Crime Scene Documentation
Taking notes Videotaping Photographing Sketching
Crime Scene Documentation
Taking Notes of the Crime Scene
Record activities including:Notification of personnel Arrival InformationScene Description (environment, evidence)Victim Description
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
Narrate the video or discuss contents Edit original video
DO NOT:
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
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
Triangulation Baseline Polar Coordinates
e e e
30°
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
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
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
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
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
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
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
Case Study: Homicide Scene
VictimSuspects
Crime Scene
top related