A California appeals court tossed out a law that banned grand juries from determining whether police officers involved in fatal shootings should face criminal charges.
The 2015 law sought more transparency in shooting investigations by shifting charging decisions from closed-door grand juries to prosecutors.
The 3rd District Court of Appeal ruled Tuesday that lawmakers can't restrict grand juries' constitutional authority to issue criminal indictments.
"To allow the Legislature to restrict this constitutional role in part would be to concede the power to restrict it in its entirety," Justice M. Kathleen Butz said in the ruling.
The California Legislature adopted the law after grand juries in New York and Missouri declined to indict officers who fatally shot unarmed black suspects, decisions that led to nationwide protests and unrest.
Supporters of the law said the secret nature of grand jury decisions can create the impression that the process is unfair and erode trust in law enforcement, particularly when the outcome seems to conflict with witnesses or cellphone video.
The law left the decision to file charges in deadly police force cases to prosecutors, who have been accused of using grand juries to avoid political fallout from their charging decisions.
The office of the state senator who wrote the law, Holly Mitchell, D-Los Angeles, did not immediately have comment.
The appeals court said the Legislature could seek a constitutional amendment banning grand juries from investigating deadly police use-of-force cases or revise the procedural rules that make those grand jury investigations secret.
Prosecutors who challenged the law said grand juries gave them power to force witnesses to testify and could involve more thorough investigations.
Grand juries are composed of community members who weigh evidence presented by prosecutors behind closed doors.
Instead of banning the use of grand juries in deadly police force cases, transcripts of their investigations should be made public, said Mark Zahner, CEO of the California District Attorneys Assn., which opposed the law. He said that could make the process even more transparent than an investigation by a prosecutor.
"Our position was always that there's no backroom, sneaky skullduggery going on in these things," he said.
The ruling came in the case of a fatal June 2015 shooting by South Lake Tahoe police. El Dorado County District Attorney Vern Pierson challenged the law by seeking a grand jury investigation of the shooting.