Biological evidence must be retained in accordance with Title 22 OS 1372.A. "A criminal justice agency having...custody of biological evidence from a violent felony offense...shall retain and preserve that biological evidence for such a period of time as any individual convicted of that crime remains incarcerated." Title 74 OS 150.28b.D “A collected sexual assault evidence kit, whether tested or untested, must be retained in a secure, environmentally safe manner for not less than fifty (50) years or for the length of the statute of limitations for the alleged crime, whichever is longer.”
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Frequently Asked Questions
Frequently Asked Questions
How long should biological evidence be retained?
How should evidence be packaged for submission to the Forensic Biology Unit?
How should samples be collected and packaged for submission to the Forensic Biology Unit?
Samples should be collected in a way that will avoid sample destruction and degradation. Biological evidence is best preserved in a dry, cool environment. Items of evidence should be packaged in brown paper sacks, evidence envelopes, or similar paper packaging material. Biological evidence should never be packaged in plastic bags. Please reference “Evidence Packaging and Submittal Tips” and information located under the Evidence Submission tab at Quality System Overview | Oklahoma State Bureau of Investigation for additional guidance.
What is a known reference sample, and how should it be collected?
A known reference sample is DNA taken directly from a person (i.e. victim or suspect). A buccal swab is DNA collected from inside a person’s mouth. To collect buccal swabs, hold the sticks of two sterile swabs together and rub the swab ends along the inside of the person’s cheek and gum area. Allow the swabs to air dry in a swab box or other appropriate container. Package the dried swabs into a container that is clearly labeled with the person's name. Buccal swabs do not need to be refrigerated. Known reference samples from the medical examiner’s office are typically submitted on a blood card.
How long will it take to get results on the evidence that was submitted?
Every case is different. The timeframe for analysis is dependent on the number of samples that were submitted and the current number of pending cases of the laboratory at the time. The duty biologist or supervisor of the laboratory analyzing the evidence may be contacted to get an estimate of the turn-around time. Estimates should not be mistaken for guaranteed time frames.
NOTE: The timeframes change over time, so please call often to get current average turnaround times.
Are samples consumed in the DNA process?
In most cases, the amount of sample that is required for DNA analysis is minimal, and every effort is made to preserve at least half of the stain for additional testing if necessary. If a sample will be consumed in testing, the laboratory will contact the assigned officer or District Attorney’s office to obtain written permission to consume the sample.
Should cases without suspects be submitted?
Yes, crime scene evidence DNA profiles can be entered into the Combined DNA Index System (CODIS) database (as long as they meet the eligibility requirements set forth by the FBI) and searched for investigative leads. When there is a CODIS hit to a subject, a letter will be sent to the investigator. The investigator should collect a known reference sample (buccal swab) from that individual and submit it to the laboratory so comparisons can be made between the reference sample and evidence profiles.
What is CODIS?
The Federal Bureau of Investigation facilitates the use of a national DNA database, which is called the Combined DNA Index System (CODIS) database. It can be used to search profiles within the state of Oklahoma and throughout the United States. CODIS is a useful tool in providing investigative leads to law enforcement agencies throughout the state. It is particularly useful when there are no suspects or a suspect has not yet been developed for a case. CODIS is also providing useful information on cold cases.
I need a paternity test, but my child’s father is deceased. I know he was in prison in Oklahoma, can I get his profile for the paternity test?
No, offender DNA samples/profiles are confidential and cannot be released for use in a civil case. Suggestions for other samples to consider for this resource: paternal grandparents, paternal (full) siblings, medical samples such as biopsy slides, or teeth.
Can I use the offender collection kit to submit a known sample for a case?
No, the offender collection kits are for the DNA database only. They do not have a chain of custody associated with them and are not considered evidence. You do not need a special kit to collect a known DNA sample. Using sterile swabs and storing them in a sealed evidence envelope is sufficient.
I received a CODIS hit letter. The letter indicates I need to get a search warrant to collect a known DNA sample from the listed individual. Why do I need another DNA sample?
Offender samples used by the DNA offender database do not have an associated chain of custody and are generally inadmissible in court. In order for the DNA evidence to be presented in court, an additional DNA report needs to be issued. A new known DNA sample with documented chain of custody is needed for this report in order to perform a direct comparison between the individual listed in the CODIS hit letter and the DNA profile obtained from the crime scene evidence. In addition, no statistical analysis, which is a required component of DNA reports, can be performed without a known DNA sample that has a properly documented chain of custody.
How do I know if a case is CODIS eligible.
- 1. The evidence submitted has to be from a crime scene
- 2. The evidence cannot be seized from the suspect’s person or his/her possession
- 3. The profiles developed are not from the victim(s)
Please remember, evidence can be informative for your case without being CODIS eligible; for example, victim blood on suspect pants. For additional guidance or to discuss a specific case, please contact the CODIS Unit at 405-330-6724.
What is the difference between touch and brief contact DNA?
Touch DNA is referring to a source of DNA likely to be from skin cells that are transferred from a person to an object after extended physical contact. Examples of touch DNA items are cigarette butts, some clothing, straws, bottles, cans, etc. DNA analysis can be performed on touch DNA items, and it oftentimes results in robust DNA information.
Brief contact items are unlikely to contain sufficient transfer of skin cells to the object. Examples of items to contain what is referred to as brief contact DNA include door handles, papers, visible fingerprints on a surface, countertops, etc. DNA analysis will generally not be performed on brief contact items at the OSBI laboratories.