physical evidence l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Physical Evidence PowerPoint Presentation
Download Presentation
Physical Evidence

Loading in 2 Seconds...

play fullscreen
1 / 8

Physical Evidence - PowerPoint PPT Presentation


  • 143 Views
  • Uploaded on

Physical Evidence. Chapter 3. Common Types of Physical Evidence. Identification To determine the physical or chemical identify of a substance – what is this? Examples: white powder, residues from debris of fire, hair etc. . Comparison

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Physical Evidence' - marc


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
significance of physical evidence
Identification

To determine the physical or chemical identify of a substance – what is this?

Examples: white powder, residues from debris of fire, hair etc.

Comparison

A comparison analysis subjects a suspect specimen and a control specimen to the same tests and examinations for the ultimate purpose of determining whether or not they have a common origin.

Significance of Physical Evidence
significance of physical evidence4
Significance of Physical Evidence
  • The probability that the specimen came from the crime scene must always be considered. See Page 104 in text for glass refractive indexes as an example.
significance of physical evidence5
Individual Characteristics

When evidence can be associated with a common source with an extremely high degree of probability; unique

Class Characteristics

When evidence can be associated with a group and never with one single source; used to place a suspect at a scene

Significance of Physical Evidence
significance of physical evidence6
Significance of Physical Evidence
  • Examples of Class vs Individual Characteristics
    • Blood ABO type is class
    • DNA is individual
    • Shoe impression would be class
    • If the shoe impression has specific wear marks it can be considered individual
significance of physical evidence7
Significance of Physical Evidence
  • Combination of many different pieces of class evidence raises the probability of an event
  • Physical evidence can be used to eliminate a suspect.
  • When does evidence pass from class to individual status?
significance of physical evidence8
Significance of Physical Evidence

Crime Scene Reconstruction

  • Purpose: supports the likely sequence of events by the observation and evaluation of physical evidence, as well as witness statements.
  • Often involves medical examiner, analysis of blood spatter, determining direction and distance from shooting source; GSR