- 1: Types of Evidence
- 2: Types of Crime Scenes
- 3: Evidence Collection
- Collection Priority
- Control Samples
- Reference Sample Collection
- Equipment
- Procedures
- Biological Evidence Packaging
- Blood and Body Fluid Collection
- Hair and Fiber
- Wet Stains on Absorbent Surfaces
- Special Situations
- Wet Stains on Nonabsorbent Surfaces
- Dry Stains on Absorbent Surfaces
- Dry Stains on Nonabsorbent Surfaces
- Collecting a Sample From a Smear
- Evidence Marking
- Packaging for Transport
- Chain of Custody
- Preserving Evidence
- Reporting
- Testifying
- Summary
- 04: CODIS
Preserving Evidence
Home > 3. Evidence Collection > Preserving Evidence
From crime scene to forensic laboratory to courtroom, all evidence must be identified, inventoried and secured to preserve its integrity. It is important to demonstrate that the evidence introduced at trial is the same evidence collected at the crime scene and that access was controlled and documented. An understanding of and adherence to the rules governing chain of custody is vital for an investigator to ensure evidence admissibility in court.
Effective evidence preservation includes appropriate packaging with correct and consistent information on labeling and procedural documentation for all items.
Biological evidence should be air-dried before packaging to minimize degradation. Packaging in paper is preferred; however, some laboratories allow packaging in plastic if the sample is thoroughly dried.
Liquid samples, such as water from a toilet bowl or pipes, should be properly documented and packaged in sterile glass or plastic containers and refrigerated as soon as possible.
