Semen Identification

When evidence is submitted in a sexual assault case with a suspect identified, the evidence will be examined as appropriate to:

• Locate semen stain visually or by alternate light source
• Examine microscopically for spermatozoa (sperm)
• Test for other semen components when negative for sperm
• Perform DNA typing when requested

NOTE: Liquid semen is not needed as a known sample.

When a sexual assault evidence kit is submitted with no suspect identified, the items will be examined for semen. DNA analysis will be performed on cases that are positive for spermatozoa. The male DNA fraction from sexual assault cases will be entered into CODIS for comparison with other cases as long as it is of probative value.

Sexual assault evidence collection kits are examined as initial priority.
Victim’s clothing and bed linen will not be routinely examined for semen. An investigator may request this service by providing information which warrants the examination or indicates the likelihood that semen would be found there when not present in swabbings from the victim’s body or a sexual assault kit was not taken. Proper collection of victim’s clothing remains important, however, because it can be needed for DNA analysis in some circumstance.

Semen identification is not performed on suspect’s clothing or bed linen.