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Crime Scene Investigation

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Presentation on theme: "Crime Scene Investigation"— Presentation transcript:

1 Crime Scene Investigation

2 Crime Scene Investigation
Defining the Crime Scene Information Obtained from a Crime Scene Processing the Crime Scene

3 Crime Scene Investigation
Defining the Crime Scene Information Obtained from a Crime Scene Processing the Crime Scene

4 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

5 Defining the Crime Scene
Location of Criminal Activity Primary = where the original crime occurred Secondary = subsequent crime scenes Let’s look at an example

6 Primary vs. Secondary Tom Bosley Scott Baio

7 Primary vs. Secondary Tom Bosley Primary Crime Scene Scott Baio

8 Primary vs. Secondary Tom Bosley Secondary Crime Scene Scott Baio

9 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

10 Macroscopic vs. Microscopic
Tom Bosley Macroscopic = McDonalds Area (Tom Bosley’s body, Chachi, the dumpster, etc.) Scott Baio

11 Macroscopic vs. Microscopic
Tom Bosley GSR on Baio’s hand Microscopic Scott Baio

12 Macroscopic vs. Microscopic
Tom Bosley’s Leg Wound Tom Bosley Microscopic Scott Baio

13 Defining the Crime Scene
Type of Crime Committed Homicide, Robbery, Sexual Assault, etc. Physical Location of Crime Scene Indoors, Outdoors, Vehicle, etc.

14 Crime Scene Investigation
Defining the Crime Scene Information Obtained from a Crime Scene Processing the Crime Scene

15 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 criminal’s repeated behavior.

16 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

17 Info from Scene Suspect Victim Object Crime Scene

18 Info from Scene All found at scene

19 Info from Scene Bullet in Bosley

20 Info from Scene Fingerprints on gun

21 Info from Scene Baio’s Hair on Bosley

22 Baio’s suspenders’ button
Info from Scene Baio’s suspenders’ button In dumpster

23 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

24 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

25 Info from Scene Reconstruction of Crime 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

26 Crime Scene Investigation
Defining the Crime Scene Information Obtained from a Crime Scene Processing the Crime Scene

27 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.

28 Processing the Crime Scene
First Officer on the Scene Securing the Crime Scene Crime Scene Survey Crime Scene Documentation Searching the Crime Scene Collection of Physical Evidence

29 Processing the Crime Scene
First Officer on the Scene Securing the Crime Scene Crime Scene Survey Crime Scene Documentation Searching the Crime Scene Collection of Physical Evidence

30 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

31 Processing the Crime Scene
First Officer on the Scene Securing the Crime Scene Crime Scene Survey Crime Scene Documentation Searching the Crime Scene Collection of Physical Evidence

32 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

33 Processing the Crime Scene
First Officer on the Scene Securing the Crime Scene Crime Scene Survey Crime Scene Documentation Searching the Crime Scene Collection of Physical Evidence

34 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

35 Processing the Crime Scene
First Officer on the Scene Securing the Crime Scene Crime Scene Survey Crime Scene Documentation Searching the Crime Scene Collection of Physical Evidence

36 Crime Scene Documentation
Taking notes Videotaping Photographing Sketching

37 Crime Scene Documentation
Taking Notes of the Crime Scene Record activities including: Notification of personnel Arrival Information Scene Description (environment, evidence) Victim Description

38 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

39 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

40 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 30° e e e Triangulation Baseline Polar Coordinates

41 Processing the Crime Scene
First Officer on the Scene Securing the Crime Scene Crime Scene Survey Crime Scene Documentation Searching the Crime Scene Collection of Physical Evidence

42 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

43 Processing the Crime Scene
First Officer on the Scene Securing the Crime Scene Crime Scene Survey Crime Scene Documentation Searching the Crime Scene Collection of Physical Evidence

44 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

45 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

46 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

47 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

48 Case Study: Homicide Scene
Crime Scene Victim Suspects


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