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
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.