Gov. Jerry Brown signed legislation Tuesday making California the first state in the nation to ban the use of grand juries to decide whether police officers should face criminal charges when they kill people in the line of duty.

The ban, which will go into effect next year, comes after grand juries in Ferguson, Missouri, and Staten Island, New York, made controversial decisions in secret hearings last year not to bring charges against officers who killed unarmed black men, sparking protests across the country. Calls for transparency also have come amid national concerns about disparate treatment of blacks and other racial minorities when encounters with cops turned deadly in Baltimore, Cincinnati and South Carolina.

“What the governor’s decision says is, he gets it — the people don’t want secrecy when it comes to officer-involved shootings,” said retired judge and former San Jose independent police auditor LaDoris Cordell, the first African-American appointed as a judge in Northern California and a key supporter of the bill. “We’re not trying to get more officers indicted. We’re saying, ‘Whatever you decide, do it in the open.'”

The governor Tuesday also signed a bill by state Sen. Ricardo Lara, D-Bell Gardens, that makes it clear it is legal to take a photograph or video of a police officer while the officer is in a public place or in a place the person photographing the action has a right to be. Both bills are the first of a wave of Ferguson-inspired criminal justice reforms now making their way through the Legislature.

The grand jury ban accomplishes officially what many California district attorneys, including in Santa Clara and Los Angeles counties, are doing already — deciding themselves whether to bring criminal charges against police officers rather than presenting evidence in a closed hearing to a grand jury and letting the panel decide. Only one other state — Connecticut — bans the use of grand juries for all criminal indictments, but that taboo dates back to the early 1980s and has nothing to do with the current protests over the treatment of people of color by police.

Supporters of California’s ban, including the legislation’s author, state Sen. Holly Mitchell, D-Los Angeles, argued that Senate Bill 227 is necessary to stop even limited use of the grand jury option and to help restore trust in the criminal justice system. They contended that using a grand jury to decide if there is enough evidence to bring charges against cops serves mostly as political cover for district attorneys reluctant to impugn the police officers with whom they work closely and on whom they depend for crucial political support.

No judges or defense attorneys participate in the grand jury process, and in California, transcripts of the hearings are sealed unless someone is indicted or a judge grants permission for their release.

Mitchell, who is African-American, called the ban “an important first step in ongoing efforts to build public trust, transparency and accountability, in an atmosphere of suspicion that compromises our justice system.”

But the California District Attorneys Association and the California Police Chiefs Association opposed the ban, saying the grand jury should be preserved as an option. Imposing a blanket prohibition would discriminate against police officers on the basis of their occupation, they argued. The association suggested that the Legislature could increase transparency by allowing grand jury transcripts to be released in cases for which no one was indicted.

Mark Zahner, CEO of the California District Attorneys Association, said putting the decision in the hands of prosecutors doesn’t increase transparency, though some district attorneys issue reports explaining their rationale. Either way, he said, “It’s absolutely ludicrous to espouse or believe that police officers get treated any differently than anyone else.”

Santa Clara County District Attorney Jeff Rosen joined his fellow district attorneys in opposing the grand jury ban, saying it should be preserved as an option for communities that prefer to use it. He has not filed homicide charges against any officers since taking office in 2011. But Rosen also has not taken any of those cases to grand juries, instead opting to issue lengthy reports laying out the reasons behind his decisions.

Under the ban, district attorneys starting next year will be required to weigh the evidence against police officers and decide whether to file criminal charges, as they do in the vast majority of all cases. A judge then hears from both prosecutors and defense attorneys at a preliminary hearing before ruling whether the matter should go to trial. District attorneys whose decisions are questionable will be accountable to voters.

More than 400 people were killed by officers in California in the 2½ years from January 2014 through July of this year, authorities estimate. No figures are available on how many of the officers were charged, if any. It is rare for police to face criminal charges because prosecutors must be able to prove “beyond a reasonable doubt” that the officer acted criminally, rather than in self-defense. California law also allows an officer to use deadly force against a fleeing person if the officer believes the suspect has committed a violent felony and his or her escape would pose a significant and serious threat.

Even when a case is brought to trial, officers are rarely convicted.

In 2004, the last time an officer was charged in Santa Clara County, for instance, a grand jury in a rare open proceeding indicted state Bureau of Narcotics Enforcement agent Mike Walker on criminal charges in the fatal shooting of Rodolfo Cardenas, whom he had mistaken for a wanted parole violator. In 2005, a jury acquitted Walker of voluntary manslaughter charges. However, the state paid nearly $1 million to settle civil lawsuits filed by his family claiming excessive force.

However, in 2009, Alameda County prosecutors charged former BART police officer Johannes Mehserle with murder in the fatal shooting of Oscar Grant III at the Fruitvale BART station earlier that year. He was convicted in 2010 of involuntary manslaughter instead.

Support for the ban in the Legislature split largely along party lines, with four moderate Democrats joining Republicans to oppose it. Supporters include the California chapter of the NAACP, the ACLU and the Mexican American Legal Defense and Educational Fund (MALDEF).

Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com @tkaplanreport.