SAN FRANCISCO (AP) — San Francisco’s district attorney announced Wednesday that city prosecutors will toss out or reduce thousands of criminal convictions for cannabis dating back decades, a move allowed under a 2016 ballot measure legalizing recreational use in California.

District Attorney George Gascon said his office will dismiss nearly 3,000 misdemeanor cases and review nearly 5,000 felony cases for possible action.

'A misdemeanor or felony conviction can have significant implications for employment, housing, and other benefit.'

George Gascon, San Francisco District Attorney

Proposition 64 legalized the recreational use of marijuana. It also allowed people convicted of marijuana charges to petition courts to toss out the cases or reduce penalties.

But Gascon says that process can be time consuming and costly, so prosecutors in the district attorney’s office plan to review and wipe out eligible cases en masse. Some people with convictions may not know they are eligible, Gascon said.

“A misdemeanor or felony conviction can have significant implications for employment, housing, and other benefit,” Gascon said. He said prosecutors will review cases from 1975 through passage of Proposition 64 in November 2016.

Gascon said 23 petitions for dismissal or reduction have been filed in San Francisco since passage of Proposition 64.

As of September 2017, around 5,000 people had applied for a change to their records, according to state data. That’s a fraction of the people that experts estimate are eligible.

Laura Thomas, deputy state director for the pro-marijuana organization Drug Policy Alliance, estimated more than 100,000 people are eligible to have their records changed.

Assemblyman Rob Bonta, a Democrat from Oakland, introduced legislation on Jan. 9 that would require county courts to automatically expunge eligible records.

Recreational marijuana became legal in California last year, and on Jan. 1 it became legal for licensed dispensaries to sell it to non-medical patients.

The U.S. Justice Department announced last week it’s halting an Obama-era policy to take a hands-off approach toward states that have legalized marijuana, still illegal under federal law. That could lead to increased prosecutions of marijuana sellers and growers, although it’s unclear how aggressive federal attorneys will be. More than half of states have legalized or decriminalized the drug and lawmakers in those states pledged forcefully to defend their policies.