OAR 137-140-0050
General Collection and Preservation Guidelines for Biological Evidence


General collection guidelines.


Custodian personnel responsible for the detection and collection of biological evidence should be aware of applicable laws governing searches, seizures, and search warrants.


Custodians may assign responsibility for biological evidence detection, collection, preservation, retention, and cataloging to appropriate personnel of varying occupations and levels of expertise, for example law enforcement personnel, medical examiners, and medical personnel.


Custodians shall ensure that its personnel are properly trained in biological evidence detection, collection, preservation, retention, and cataloging techniques. Training must include, but not be limited to, record-keeping protocols; crime scene search techniques; rules of evidence handling; safety concerns of biological evidence handling and detection techniques; legal aspects of search warrants, searches, and biological evidence recovery; chain-of-custody documentation and requirements; proper storage techniques for biological evidence; detection, collection, and preservation methods used for biological evidence; and contamination prevention.


General preservation guidelines.


Custodians shall store and preserve biological evidence in the manner set forth in ORS 133.705 (Definitions for ORS 133.705 to 133.717) to 133.717 (Provision of notice or order to defendant) and these administrative rules when biological evidence is either:


Collected as part of a criminal investigation of any covered offense; or


In the possession of the custodian and reasonably may be used to incriminate or exculpate any person for any covered offense.


Custodians should, whenever possible, collect and preserve biological evidence from physical evidence in an amount and manner that is sufficient to develop a DNA profile.


When physical evidence is of a size, bulk, or physical characteristic as to make preservation and retention of the entire physical evidence impracticable, custodians shall remove and preserve portions of the physical evidence likely to contain biological evidence in a quantity sufficient to permit future DNA testing. Thereafter, custodians may return or dispose of the physical evidence according to the custodian’s policies and practices.


General drying guidelines. In general, moisture can degrade DNA. If possible, custodians should dry wet or moist biological evidence and package it into clean and previously unused paper containers (for example envelopes, bags, cardboard boxes). If custodians cannot air dry evidence, custodians should refrigerate liquid evidence and freeze wet evidence. When drying wet or moist biological evidence, custodians should:


Air dry physical evidence thoroughly;


Place wet or moist evidence in a secure environment or locked room that has ventilation in order to prevent contamination;


Take care not expose physical evidence to excessive heat or sunlight; and


Take steps to prevent cross-contamination.


General packaging guidelines. Appropriate preservation and packaging techniques of biological evidence vary, and custodians should use appropriate clean packaging to prevent loss, degradation or contamination of biological evidence. Custodians should:


Properly seal all evidence packages in a manner to prevent tampering and eliminate loss or contamination of the biological evidence through open edges;


Contact the Oregon State Police Forensic Services Division for questions about appropriate techniques for unique items of biological evidence.

Source: Rule 137-140-0050 — General Collection and Preservation Guidelines for Biological Evidence, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=137-140-0050.

Last Updated

Jun. 8, 2021

Rule 137-140-0050’s source at or​.us