The proposed legislation would change the current "reasonable force" rule to a "necessary force" standard.
That means officers would be allowed to shoot only if "there were no other reasonable alternatives to the use of deadly force" to prevent imminent serious injury or death, said American Civil Liberties Union legislative advocate Lizzie Buchen, whose organization is among the groups behind the bill.
The goal is to encourage officers to try to defuse confrontations or use less-lethal weapons, said Terry Schanz, a spokesman for Assemblyman Kevin McCarty of Sacramento. McCarty is co-authoring the bill with fellow Democratic Assemblywoman Shirley Weber of San Diego.
"They'd have to able to show that this was the only option you had," McCarty said. "You couldn't utilize other tactics, you couldn't bring in reinforcements, you can bring in maybe the canine unit."
Leslie McGill, executive director of the California Police Chiefs Association, and Cory Salzillo, a lobbyist for the California State Sheriffs' Association, said they hadn't seen the proposed bill and couldn't comment.
The proposal comes after two Sacramento police officers chased Stephon Clark, who was suspected of breaking into cars, into his grandparents' backyard. They say they shot at him because they thought he had a gun, but investigators found only a cellphone.
California's current standard, set in law and by court decisions, means it is rare for police officers to be charged following a shooting and rarer still for them to be convicted. Frequently it's because of the doctrine of reasonable fear: If prosecutors or jurors believe that officers have a reason to fear for their safety, they can use force up to and including lethal force.
That standard "gives very broad discretion for using deadly force," said Buchen. "It doesn't mean there has to have been a threat. If a reasonable officer could have perceived a threat and responded with deadly force, then it's legal."
The proposed standard could require officers to delay confronting a suspect they fear may be armed until backup arrives, for instance, or to give explicit verbal warnings that the suspect will be killed unless he or she drops the weapon, she said. Officers might also have to first engage in de-escalation techniques or try non-lethal weapons if possible before shooting.
The proposed bill would also make it clear that the use of deadly force wouldn't be justified if the officer's gross negligence contributed to making the force "necessary." It would open officers who don't follow the stricter rules to discipline or firing, or sometimes to criminal charges.
The ACLU says California would be the first state to adopt such a standard, though some other law enforcement agencies including San Francisco have similar or even more restrictive rules.
The bill has its opponents.
"To take that judgment element out of the equation is to effectively deny them the right to protect themselves," said former Sacramento County Sheriff John McGinness.
McGinness said he sees multiple issues with the bill and possible wording change.
Along with wanting police to be able to protect themselves McGinness also believes law enforcement already do everything they can not to open fire.
"Law enforcement officers do not go about the performance of their duties with a desire to find themselves to be caught up in this type of situation," McGinness said. "Nobody wants it, it's a horrible experience. But there's also a recognition of the fact that sometimes those occasions develop and which nothing else will work."
Officers fatally shot 162 people in California last year, only half of whom were armed with guns, according to the lawmakers. They cited studies showing blacks are far more likely than whites to die in police shootings, and that California has five of the nation's top 15 police departments with the highest per capita rates of police killings: Bakersfield, Stockton, Long Beach, Santa Ana and San Bernardino.
Separate legislation proposed by Democratic state Sen. Nancy Skinner of Berkeley would make law enforcement records on officer use of force, on the job sexual assault or dishonesty available to the public. Current California law is among the nation's most secretive, Skinner says, arguing that more disclosure would promote better public trust.
The first step for this bill is going to the Assembly Public Safety Committee. They will start discussing it in the next few weeks.