California leaders introduce legislation to ban police from using rape kit DNA to probe other crimes

California state senator Scott Wiener and San Francisco District Attorney Chesa Boudin introduced new legislation Monday that would bar law enforcement agencies from keeping victim DNA obtained though rape kits in searchable databases that could be used to identify suspects in crimes.

The new legislations, introduced as Senate Bill 1228, was introduced following revelations last month by the district attorney’s office that an unidentified suspect in a recent property crime in San Francisco had been identified though DNA from the scene that matched with a woman’s DNA from a sexual assault exam in 2016.

Boudin said he dropped the charges against the woman, whom he did not identify. Police Chief Bill Scott said he’s amended the department’s crime lab policies that allowed a victim of a sexual assault to be identified as a suspect.

"Victims of sexual assault should be encouraged and supported in coming forward to undergo sexual assault examinations to identify their perpetrator," Boudin said in a statement Monday. "Instead, the practice by a police crime lab that my office exposed treats victims like criminals. It not only violates their privacy, but it dissuades victims from reporting sexual violence — which makes us all less safe."

Mark Powell, who manages the department’s crime lab, explained how the rape kit DNA was used to identify a suspect at Wednesday’s Police Commission meeting.

He said that the lab created a "quality assurance" database to rule out contamination. The database contains DNA from lab staff, investigators and any profiles technicians work up in the lab – like sexual assault cases.

Powell said investigators first run profiles of unknown suspects in the quality assurance database to make sure they’re not uploading contaminated DNA into the state and federal Combined DNA Index System – or CODIS. He said the lab created the quality assurance database in 2015.

But at some point between 2015 and 2022, Powell said the lab begin seeing DNA matches in the quality assurance database that didn’t match in CODIS that they reported to investigators anyway.

Scott said the lab has since ended that practice.

The chief also said Monday that he fully supports the legislative efforts to protect sexual assualt survivors. 

"We must never create a disincentive for sexual assault survivors — or any crime victim — to cooperate with police," Scott said in a statement.