San Francisco District Attorney Chesa Boudin was set to launch a slate of new policy directives on Friday aimed at reducing racial disparities in the criminal justice system and mass incarceration, including ending the charging of cases where contraband was obtained through “pretextual” traffic stops.

Boudin is also making good on his campaign promises to stop charging gang enhancements and ending the use of California’s “three strikes” law — the latest of several reforms to the office since he was sworn in on Jan. 8.

“Racial bias in the criminal justice system is something we need to address if we’re going to restore trust and confidence in the system, especially with communities of color that are so disproportionally affected by crime,” said Boudin, a former public defender who ran on a progressive platform.

Pretextual stops are when a police officer pulls a driver over for a minor traffic infringement with the aim to search them, often for drugs.

Such stops have long been criticized by criminal justice reform advocates, who say they lead to disproportionate arrests for African Americans and poor people — much like New York’s stop-and-frisk program. The U.S. Supreme Court found pretextual stops constitutional in 1996.

“This is a national issue,” Boudin said. “All the Democratic presidential candidates are talking about stop-and-frisk, and just as in stop-and-frisk, African Americans are more likely to experience these pretextual stops.”

Boudin, though, said the policy around pretextual stops “is very, very narrow.” It only applies to cases where police find contraband during an “alleged consensual search.” It does not apply when contraband is in plain view or if an officer makes a stop and discovers something more serious like a murder weapon or kidnap victim.

The U.S. Department of Justice found that African American drivers were disproportionately stopped and searched compared with their representation in the driving population. And a 2020 report by the California Department of Justice found that black drivers in San Francisco are stopped at five times their representation in the city’s population — a disparity that’s greater than in Los Angeles or San Diego.

The San Francisco Police Department said it is working to address racial disparities in traffic stops under its collaborative reform initiative that began in 2016 following a top-to-bottom review by the Justice Department.

Boudin said he will also stop charging gang enhancements against defendants, which can add years to felony sentences, and end three-strikes penalties.

Gang enhancements have drawn opposition in California following studies showing they are disproportionately applied to people of color in poor neighborhoods. The enhancements, though, are seen by many law enforcement groups as an important tool to hold gang members accountable.

California’s three-strikes law was approved by voters in 1994, allowing prosecutors to seek 25-years-to-life sentences for defendants on a third offense, or “strike.”

In 2012, California voters approved changes to the law to limit third strikes to serious or violent felonies.

Boudin said exceptions to the policies may be made “under extraordinary circumstances.”

In cases where a defendant presents grave risks to public safety or crime victims, the district attorney or a designee may override the policy.

Evan Sernoffsky is a San Francisco Chronicle staff writer. Email: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky