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KNOWN SAMPLE COLLECTION

NEEDING KNOWN SAMPLES FOR CODIS ENTRIES

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Do you think the evidence submitted is linked to the victim?
If your answer is YES, this known sample from the victim should always be submitted, but this evidence cannot be run through CODIS.

If your answer is NO, you don’t think it is the victim (we still need victim known), this sample may be eligible to be run through CODIS.

Do you think the evidence submitted is linked to the suspect?
This sample can be run through CODIS but a known sample from the suspect should be submitted to avoid a delay in receiving your reports. If you don’t submit a known sample from the suspect and there is a CODIS hit, expect a 30- 45 day delay in your results.

If you don’t submit a known from the suspect, and the evidence is eligible to run through CODIS, a known sample will be requested in the report you receive.

Do you think the evidence submitted is linked to a unrelated, third party that is not involved in the crime?
Elimination samples can be submitted for consensual partner(s) or owners of a property allowing for any foreign profiles to be run through CODIS.

VICTIM EXAMPLE SUSPECT EXAMPLE
A rape kit sample is submitted and we locate a foreign profile on one of the swabs. This profile will be run through CODIS. The case officer will be notified via SDFL Report if there was a CODIS hit. A known sample from the suspect will be requested in the report. This is needed to start the chain of custody and so the evidence is admissible in court. Sheets from the suspect's bedroom are submitted as evidence. Looking for victim on the suspect’s bed sheets. Known samples from both the suspect and victim must be submitted, but this evidence would not be run through CODIS. Victims are not uploaded into CODIS and neither are evidence samples where the suspect is expected to be.

COLLECTING KNOWN SAMPLES

CODIS exmaple

Y-STR TESTING

Y-STR testing tests the Y-chromosome, looking only at male DNA. This DNA is passed on paternally, minus any mutations.

Although Y-STR testing is not CODIS eligible, this testing offers a great advantage to cases where very little male DNA is present and there is an overabundance of female DNA. It is also helpful when there is a possibility of multiple male DNA mixtures.

When running Y-STR testing you must have a suspect known sample to run and compare against.

Prioritize Your Evidence

If you are having trouble prioritizing your evidence, or have questions about what exams to choose, please contact the SD Forensic Lab at 605-773-7843.