steps
- Processing Physical evidence
- Record the scene
- Systematically search for evidence
- Collect and package physical evidence
- Maintain Chain of custody
- Obtain controls
- Submit evidence to the laboratory
who evaluates the crime scene?
the first officers to arrive
why do they protect the scene?
to protect the integrity of any evidence
ways to record the scene
- photography - pictures of an unaltered scene; overviews and closeups; videotaping may be used
- sketches - rough sketch containing accurate measurements then final sketch drawn with care
- notes - detailed description of the scene
searching methods
- spiral
- grid
- strip/line
- quadrant/zone
integrity
evidence should maintain its original characteristics to have a value as evidence
general rules to package evidence
use separate containers; submit to lab intact; items of clothing are to be air dried and placed in individual paper bags
all evidence that may degrade should be packaged in containers that….
allow the flow of air
charred materials should be packaged in….
air tight containers
why do we obtain controls?
to compare with a known standard
example of control factor:
fingerprint from suspect
when submitting the evidence to a lab….
it is a personal delivery; evidence submission form accompanies all evidence
