William Scott, the San Francisco police chief, announced on Wednesday that his department would no longer release mug shots of people who had been arrested unless there was an immediate public safety reason to do so.

“This policy emerges from compelling research suggesting that the widespread publication of police booking photos in the news and on social media creates an illusory correlation for viewers that fosters racial bias and vastly overstates the propensity of Black and brown men to engage in criminal behavior,” Chief Scott said in a statement.

Many newsrooms have already started removing mug shot galleries, citing the same reasoning.

Last month, dozens of outlets once owned by the newspaper chain GateHouse Media said they would stop using slide shows of mug shots that were not part of a news article. Those sites are now run under the banner of Gannett, which merged last year with GateHouse and had already removed mug shot galleries from its sites, said Amalie Nash, USA Today Network vice president for local news and audience development.