COLUMBIA, Mo. (AP) – Advocates against sexual violence say Missouri’s lack of evidence testing in some sexual assault cases make it harder to link repeat offenders to more than one victim.

Law enforcement officials say many agencies don’t send evidence for testing unless the victim wants to go forward with potential charges. They say testing every evidence kit would also add to Missouri’s already extensive backlog.

The Columbia Missourian reports Missouri hasn’t done a statewide audit on the number of untested evidence kits.

Advocates say the inaction makes it more difficult to identify repeat offenders. The advocacy group Joyful Heart Foundation says that even if a survivor knows the attacker and chooses not to pursue charges, the attacker’s DNA can still be matched to other victims if the evidence is tested.