The San Francisco police crime-lab technician and a supervisor implicated in alleged misconduct that could jeopardize hundreds of criminal cases failed a DNA proficiency exam last year and were barred from processing evidence, documents show.
Police Chief Greg Suhr said Monday that authorities were looking at 1,400 criminal cases that were prosecuted in part based on DNA work done by the technician — identified in court records as Mignon Dunbar — and her supervisor, Cherisse Boland. Both are civilian police employees.
It’s the latest embarrassment for the crime lab, where the 2010 theft of cocaine evidence by a drug-tester ultimately led to the dismissal of 1,700 criminal cases on which she had worked.
“We’re going to do a complete audit of any work these criminalists touched,” Suhr said of the DNA tests. “If we do discover there’s any problem, all those cases will be reworked until they’re to the appropriate standard.”