25.00.061               DNA EVIDENCE COLLECTION                  (CALEA 83.2.7)

 

A DNA (deoxyribonucleic acid) match is a major factor in solving cases where the identity of the offender is not known.  Personnel must have a good understanding of where DNA can be found, how to avoid contamination and preserve fragile DNA evidence.  Agency personnel who specialize in evidence collection must have special training in collecting and preserving DNA samples for analysis.

 

If a first responder determines the need for DNA collection, he or she shall notify his or her supervisor and request investigative and forensic assistance.  The supervisor shall consult with the supervisors of the Investigations Unit and the Forensic Unit to determine the need to have an investigator and or forensic technician to respond to the scene to assist with evidence collection and preservation.   The first responder shall work together with the investigators and laboratory personnel to determine the most probative pieces of evidence and to establish priorities. 

 

The first responder shall:

 

·         adhere to the “Bloodborne Pathogens Exposure Control Plan”

·         use universal precautions when handling biological specimens or stains

·         be familiar with the techniques to identify, collect, and preserve DNA evidence from sources such as blood, semen, skin cells, tissues, organs, muscles, bones, brain cells, teeth, hair saliva, mucus, perspiration, fingernails, urine and feces

·         be familiar with sources of collection techniques to preserve DNA evidence on items such as clothing, eyeglasses, tissue, cigarette butts, bottles, glass, tapes, ropes, ligatures, bedding, hair brushes, and other items that may contain human tissue or fluid samples

·         work as a team with the investigators and forensic personnel to package and preserve any items according to current Department practices and training 

 

Biological evidence is fragile and can easily be destroyed.  The recognition and recovery of such evidence must be performed properly by the investigator to make the best use of it.  If there are any questions, call the Forensic Unit or the Local Crime Laboratory.

 

The investigator/gatherer shall:

 

·         adhere to the “Bloodborne Pathogens Exposure Control Plan”

·         use universal precautions when handling biological specimens or stains

·         wear gloves and change them often

·         use disposable instruments or clean them thoroughly before and after handling each sample

·         avoid touching the area where DNA may exist

·         avoid talking, sneezing, and coughing over evidence

·         avoid touching his/her face when collecting and packaging evidence

·         air-dry evidence thoroughly before packaging, keep the evidence dry and at room temperature

·         avoid direct sunlight and warmer conditions, such as a police car without air        conditioning

·         put evidence into new paper bags or envelopes, not plastic bags

·         not use staples

·         seal, label and transport the evidence to ensure proper identification of where it was found and the proper chain of custody

·         contact the State Crime Lab or the Department’s Forensic Services Unit for long-term storage issues 

 

Agency personnel that specialize in evidence collection must have special training in collecting and preserving DNA samples for analysis.  Training shall include but not be limited to:

·         identification of DNA evidence sources

·         information about DNA databases and their potential to provide leads in current and “cold” cases

·         evidence collection and storage techniques

·         use of DNA evidence in court

 

 

DNA samples may be submitted only to laboratories accredited for law enforcement DA analysis by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB) OR THE National Forensic Science Technology Center (NFSTC). 

 

Preparation of DNA evidence for submission to an accredited laboratory shall comply with Department evidence packaging and lab submission procedures and any procedures specific to the lab that will examine the evidence.