A few hundred people hired attorneys, paid court fees and filed petitions to modify their records since November 2016, but the vast majority of convictions still remain untouched. Many district attorneys throughout the state said they lack the resources to sift through and review decades' worth of criminal cases to identify eligible convictions.

In January 2018, Gascón announced his office would take on the time-consuming task of sifting through many thousands of criminal cases to identify eligible marijuana convictions. Until then, only 23 people who hired lawyers and paid court fees took advantage of the new law in San Francisco.

"Drug use in this country occurs across economic and racial lines, but the people that end up being the subjects of the criminal justice system's attention are poor people and people of color," Gascón said. "And there's nothing just about that."

Though African-Americans make up less than 5 percent of the population in San Francisco, they account for 33 percent of marijuana-related convictions, Gascón said.

Code for America is a San Francisco-based nonprofit that seeks to use technology to make government more efficient.

Director Jennifer Pahlka said coders developed a "lightweight" and simple computer-based algorithm dubbed "Clear My Record" to quickly identify eligible cases. The program automatically fills out forms to be filed with the courts.

Pahlka said Monday that Code for America was working with several other California district attorneys to identify eligible marijuana cases in their counties.

"We believe that the work that's happened over the past several months creates a real blueprint for the future," Pahlka said. "We have the power to provide automatic records clearance to millions, and paired with a targeted set of policy actions, technology will make this possible."

In December, Michigan became the latest state to broadly legalize marijuana, eliminate pot crimes and allow past convictions to be erased or reduced. Meanwhile, prosecutors in Baltimore, Seattle, Chicago and multiple others across the country followed Gascón's lead and announced their intentions to clear eligible marijuana convictions in their jurisdictions.

Gascón and Pahlka called on prosecutors across the country to adopt Code for America's technology.

"I want to continue to evangelize, if you will, to get others around the country and the state to do the same things and push the envelope to continue to reduce the impacts of criminal convictions when we can," Gascón said.