The killing of Walter Scott by Officer MIchael Slager was caught on video, leaving no doubt that he was shot in the back while fleeing from a traffic stop. A commenter on my blog asked whether the hue and cry that has resulted means that “if you can run away from a cop, you can get away with any crime because any effort to stop your pursuit using a weapon is unlawful and wrong?”

No, but unless some very unusual mitigating information emerges, this was too much firepower considering the offense and the situation surrounding it.

But don’t take my word for it; here are the rules:

The Supreme Court held in a 1989 case, Graham v. Connor, that the appropriateness of use of force by officers “must be judged from the perspective of a reasonable officer on the scene,” rather than evaluated through 20/20 hindsight.

That standard is designed to take into account that police officers are frequently asked to make split-second decisions during fast-evolving confrontations, and should not be subject to overly harsh second guessing…

A seminal 1985 Supreme Court case, Tennessee vs. Garner, held that the police may not shoot at a fleeing person unless the officer reasonably believes that the individual poses a significant physical danger to the officer or others in the community. That means officers are expected to take other, less-deadly action during a foot or car pursuit unless the person being chased is seen as an immediate safety risk.

In other words, a police officer who fires at a fleeing man who a moment earlier murdered a convenience store clerk may have reasonable grounds to argue that the shooting was justified. But if that same robber never fired his own weapon, the officer would likely have a much harder argument.

“You don’t shoot fleeing felons. You apprehend them unless there are exigent circumstances — emergencies — that require urgent police action to safeguard the community as a whole,” said Greg Gilbertson, a police practices expert and criminal justice professor at Centralia College in Washington state.

That’s the reason the condemnation of Slager was strong from all quarters, including from police.

Police always have to make split-second judgment calls, and that can be extremely difficult. It’s part of the job, however; they should not be hampered from doing their job, but neither are they given carte blanche to be trigger-happy.

You can tell people to never fight or struggle with an officer, and not to defy him or mouth off. Wait till you get a lawyer and have the lawyer defy him and mouth off, if necessary. That’s common sense and good advice. But a lot of people, especially those who are in any sort of trouble with the law (including relatively minor trouble, such as Scott’s) are going to try to flee. You don’t want cops killing them all. There are ways to determine when it is okay to shoot and when it is not okay to shoot, and unless there are some huge surprise revelations in this case, it should have been a “not okay to shoot” case.

Slager may have shown awareness of this when he—as has been reported—appears to drop something near Scott’s body in the video, after the shooting. If he was planting evidence (the taser?), it indicates a possible awareness of guilt and attempt at a coverup.

[Neo-neocon is a writer with degrees in law and family therapy, who blogs at neo-neocon.]