The San Francisco Police Commission grilled police department leaders Wednesday about the policies and procedures that allowed officers to use DNA collected from a rape kit to link a sexual assault victim to an unrelated case.
“This was a horrendous mistake,” Police Chief William Scott. “It’s been corrected. Policies have been put in place for this to not happen again.”
Last month, District Attorney Chesa Boudin revealed his office had dropped its case against the woman, after learning how police had used her DNA. Boudin said the practice could violate victims’ constitutional rights and deter people from cooperating with law enforcement and prosecutors.
On Wednesday, Scott promised commissioners that his department will not use DNA samples collected from rape victims to investigate them for unrelated crimes.
The police chief said his department has been flooded with questions from advocates for rape victims asking, “Will my DNA be used to investigate me for crimes outside of my sexual assault?”
“The answer is ‘no,’” Scott said.
Separate DNA databases
Acting Crime Lab Director Mark Powell explained to commissioners that the police department works with two separate DNA databases, a quality assurance database and the Combined DNA Index System Database (CODIS), which the FBI uses to track convicted felons.
The department’s quality assurance database includes thousands of samples, including those from rape kits, crime scenes, crime lab technicians and lab visitors. Powell said the lab uses the database to check samples for contamination.
The lab does not upload DNA samples from sexual assault victims to CODIS, Powell said.
But when the lab ran a DNA sample collected from the scene of the property crime through both CODIS and the quality assurance database, it uncovered a match with a rape victim.
“There was a piece of the evidence that was gathered from the scene and it was run through the system, and she appeared in both the quality assurance database from her sexual assault kit, as well as the CODIS database from her prior arrests,” Police Capt. Sean Perdomo of the Investigations Bureau told commissioners Wednesday.
Commissioners said the department’s practices raised ethical concerns.
“Are you notifying victims that their DNA is being used for other purposes?” Commissioner Cindy Elias asked.
“Are we notifying victims of survivors any time their DNA is run against quality assurance for contamination purposes? The answer is ‘no,’” Scott said. He said he doubts other DNA samples from sexual assault survivors have been used to check for unrelated crimes.
Scott has acknowledged that, for seven years, the department’s crime lab has entered DNA samples collected from victims of violent crime, including children and sexual assault survivors, into the quality assurance database.
Commissioners asked why the lab has kept DNA samples in its database for years. Powell said it was common practice to retain samples for long periods of time. “It wasn’t atypical to have something take years to come into the lab,” he said.
Scott said the department is considering destroying quality assurance DNA samples after 60 days.
Scott told the commision that the department is conducting an investigation into its use of DNA evidence. Officer Peromo said that, so far, the department has identified DNA from 11 rape kits that matched another sample. Officers are investigating whether such matches were used to charge any victims.
Commissioner Ellis suggested that another oversight body, such as the City Attorney’s office, should conduct a separate investigation. Scott said that wasn’t off the table, but he would provide the commission with updates on the department’s investigation.
“We’re going to be transparent with you, with whatever we come up with,” Scott said.