Sheriff Lee Baca told the county's Board of Supervisors in a report issued last week the department had stopped shipping the evidence to crime laboratories at the end of May.
That could leave thousands of old cases to wait indefinitely, an idea that isn't sitting well with those who treat rape victims.
"Every day someone walks in here and we think did this person have to be raped, because their attacker could have been taken off the streets," said Gail Abarbanel, who runs a rape treatment center at UCLA Medical Center that sees around 1200 new cases each year. "How do we get the legal system to listen?"
Sherriff Baca said the department is counting on federal grant money expected next month for another four or five more months of testing, but only an uncertain stream of state money will follow that.
Sheriff's officials said Monday that Marshall University in West Virginia would perform a small number of tests for free each month.
The report said the department has sent evidence from 676 cases to outside labs since the new efforts to clear the backlog began. Most of those were only sent recently and had yet to be tested.
In November, it was revealed that more than 4,000 sexual assault kits sat untested in county storage, many from smaller police agencies that rely on the Sheriff's Department for lab work.
Sheriff's officials downplayed that number, suggesting that most of the cases had been resolved or pursued by other means.
They had previously tested DNA evidence only when case investigators asked, but Baca and Los Angeles police chief William Bratton said in November that all such cases would have DNA evidence tested.
In the months since, sheriff's officials often said they did not have sufficient resources to complete the project. Baca told county officials he needed $4.5 million to send out old rape kits and about the same amount to hire 30 more for the Sheriff's department lab to clear the backlog within 18 months.
County Supervisors said there was no way Baca could have that money in a badly strained budget.
"That was never realistic," Supervisor Zev Yaroslavsky said. "He's got a $2-billion budget."
Abarbanel disagrees. "This is not about money. This is about priorities," she said in a phone interview. "We shouldn't have rape kits in freezers, we should have them in court rooms as evidence."
It's not yet clear if other state, federal, or city funding could help. In May, the Los Angeles City Council approved a budget for the next two years that includes the backlogged testing of the city's untested rape kits.
"We aren't asking for special privileges," said Lindsey Horvath, President of the West Hollywood National Organization for Women. "We just want the sheriff to get the funding to do his job."
The evidence kits include items such as fingernail scrapings and body fluids, which provide valuable DNA evidence that is used in court.