A day or so after the 1984 McDonald’s massacre, I read in the Los Angeles Times that the SWAT sniper who fired the shot which killed the perpetrator was required to radio his superiors and request permission to fire a shot with the specific intent of killing the shooter. The Times article also stated that this was the first time in the history of San Diego that authorization had ever been granted for such an act. Would that still be the case today, or do LEOs now have freer reign when it comes to neutralizing an active shooter? What are modern policies now when the police respond to somebody who is in the act of indiscriminately executing civilians in a public venue, and his or her intent and capability of doing so are overwhelmingly obvious? As a hypothetical example, say an off-duty LEO is eating dinner in a crowded restaurant and an individual carrying multiple weapons and visible supplementary gear enters the restaurant and starts howling like a hyena and mowing down the patrons. If the LEO responded by immediately neutralizing the shooter with a head shot without offering the shooter the choice to surrender his actions first, would that be considered a justifiable action by police agencies now, particularly those in the United States?
The justification for use of deadly force is the same as in other circumstances, see here: Deadly force - Wikipedia
No need to offer the shooter a chance to surrender.
That 1984 sniper rule was either inaccurately reported or would quite likely have been changed later. It’s quite possible that if the sniper takes a shot when someone isn’t in imminent danger, he has to get approval from his superiors. When someone is in imminent danger, that kind of rule would either not get instituted or someone would realize the silliness of it.