Evidence Preservation
Definition
The discipline of maintaining physical evidence in its post-incident condition until all parties have had the opportunity to examine it. Includes both preventing accidental damage and preventing intentional alteration.
- Goal
- Maintain evidence in its post-incident condition until all parties examine it
- Covers
- Both accidental damage and intentional alteration
- Applies in
- Failure investigations as well as criminal casework
- Depends on
- Correct storage conditions and controlled access
Common questions
Why does preservation matter even when no wrongdoing is suspected?+
In a failure investigation, all interested parties, such as a manufacturer, an operator, and a regulator, need the opportunity to examine the same physical evidence. If it degrades or is altered before that happens, findings can be disputed on the grounds that the evidence itself was compromised.
What is the difference between evidence preservation and chain of custody?+
Chain of custody documents who handled evidence and when. Preservation is the physical and procedural effort that keeps the evidence itself unchanged. The two work together: a clean chain of custody does not help if the evidence was damaged or contaminated along the way.
Related terms
- ASTM E860
- Standard Practice for Examining and Preparing Items That Are or May Become Involved in Criminal or Civil Litigation. Specifies documentation requirements and...
- Destructive Examination
- Testing that consumes or modifies the evidence: sectioning for metallurgical mounts, chemical digestion for composition analysis, mechanical testing to failure. Requires notice...
- Hypothesis Generation and Testing
- The step in failure analysis where possible causes are listed systematically, then each is tested against the physical evidence and engineering calculations....
- Non-Destructive Examination (NDE)
- Inspection methods that do not alter or consume the evidence: visual inspection, photography, dimensional measurement, dye-penetrant testing, ultrasonic testing, and radiography. NDE...
- Root Cause
- The fundamental, underlying deficiency from which the failure originated. Distinguished from immediate cause (the final physical event) and contributing factors. Root-cause analysis...