SACRAMENTO (CBSLA) — Surrounded by family members of people killed by police, Governor Gavin Newsom signed one of the strongest use-of-force laws in the nation Monday.

Police officers are now only allowed to use deadly force when “necessary” instead of “when reasonable.”

The new law, which takes effect January 1, 2020, also allows prosecutors to consider the actions of the officer leading up to any shooting and prohibits firing on fleeing felons unless they pose an immediate danger.

“For 400 years, people of color have often had a different kind of justice in this nation. After 400 years of demonstrating our commitment and humanity to this nation, we deserve fairness and justice,” says the law’s author, San Diego Assemblywoman Shirley Weber.

The law requires officers to use other techniques to address threats instead of using deadly force when safe to do so, and encourages law enforcement to train on and use de-escalation techniques like verbal persuasion and other crisis intervention methods.

“This is a time for healing, progress and looking forward,”said Governor Newsom. “The bill goes to the heart of some of our most sacred principles, in which force should be exercised judiciously, with respect for human life and dignity. The bottom line is that deadly force should only be used when absolutely necessary,” .

The legislation is called the “Stephon Clark Law,” named after the unarmed African-American man who was shot by police in his backyard in Sacramento last year. Police claim they believed Clark, once cornered, had a gun in his hand and feared for their lives, prompting two officers to fatally shoot him. No gun was ever recovered — just a cellphone.

Stephon Clark

Clark’s family and other relatives of people who died in police shootings were on hand for the signing ceremony.

“Today is a day of justice for all of the families: Stephon Clark, Alfred Olango, Jonathon Coronel, Ezzell Ford, Oscar Grant to say just a few,” said civil rights leader Rev. Shane Harris, “This will create more transparency with law enforcement, but we know that this is [just] a first step.”