California Gov. Gavin Newsom on Monday signed into law what will arguably become the nation’s strictest standard for police use of lethal force. The new law, known as “Stephon Clark’s Law,” after the unarmed black man who was killed by police in the state Capitol last year, will usher in significant changes for police procedure when it takes effect on Jan. 1, 2020. In the new year, California police will no longer be allowed to shoot at fleeing suspects unless they pose an immediate danger, a long overdue update that dates all the way back to 1872. New language in the law also stipulates that law enforcement can only use deadly force when “necessary,” as opposed to the current wording of when it is “reasonable.”

Another crucial alteration will show its effects in the courtroom. Under the new law, prosecutors will now be able to take into account the actions of the officers and victim leading up to a fatal incident, replacing current rules that only allow prosecutors to consider the seconds surrounding use of lethal force. Broadening the timeline could allow prosecutors to view such cases with greater context. Supporters believe the expansion will also encourage departments to further emphasize de-escalation practices. Assemblywoman Shirley Weber (D), who authored the bill, called it an “aggressive effort to retrain our officers and change the culture of police.”