The Association of Los Angeles Deputy Sheriffs has this post with the above title:

Assemblywoman Shirley Weber has introduced AB 931, seeking to criminalize law enforcement's use of deadly force, and allowing prosecution for homicide if a prosecutor disagrees with a deputy's tactical decisions prior to use of deadly force. Her legislation eliminates the long-enshrined standard that such force be "reasonable," and instead replaces it with a standardless term that such force be "necessary" while also disallowing a justifiable homicide defense if tactics prior to the shooting were "grossly negligent."  The bill should be rejected by the state legislature.

Existing law in California allows any person to use deadly force in self-defense or defense of others when it reasonably appears to the person that he or others are in imminent danger of great bodily injury or death; actual danger is not required (Penal Code section 197). If a person acts from reasonable and honest convictions, they are not responsible for a mistake in the extent of danger when other persons would have also been mistaken.

Elsewhere there is a drive to weaken the "qualified immunity" standard that protects peace officers from liability, and to some extent from litigation, when they make reasonable judgments about the limits of the Fourth Amendment that later are deemed to be incorrect.

Who would want to be a peace officer if doing your duty means you can be sued or even prosecuted for misjudging the fuzzy limits of the Fourth Amendment?  And when nobody wants to be a cop any more, "who you gonna call?"