Trying to resolve whether officers' actions were justified--the question now before investigators in the case of a controversial police incident in Inglewood on Saturday--is one of the murkier areas of police discipline.
There are guidelines, but there is no precise blueprint for how police should use force. What's required varies with the situation.
Generally, police are authorized to use force, even deadly force, in defense of themselves or others. Judging whether excessive force was used is the key to cases of alleged brutality.
A number of experts were cautious in trying to assess the Saturday episode, which was partly videotaped by a witness. Mindful of past cases like the Rodney King beating, in which key elements of the event were not caught on tape, they were quick to point out that not all the facts about the Inglewood case are known.
"When you see a portion of an incident, it is important to know total context of incident from beginning to end," said Bob Stresak, a senior consultant with the California Commission on Peace Officers Standards and Training. "What initiated the stop? What knowledge were the officers armed with? What type of area was it--a high crime area? Was this initiated by suspect description related to a serious felony? All those components need to be taken into account" when evaluating use of force, he said.
Jim Pasco, executive director of the National Fraternal Order of Police, said there should be no rush to judgment because "a lot of things happened before that videotape started rolling."
But many police officers were uneasy with what they, and millions of television viewers, saw on the videotape: images of police slamming a limp, handcuffed teen-ager onto a car and then punching him in the face.
In particular, striking someone who has already been handcuffed, in most cases, violates "a cardinal rule" of use of force, said Greg Berg, a retired LAPD commander who is now director of community and safety services for Cerritos. "When someone is handcuffed, everything is finished at that point."
Inglewood police officials say 16-year-old Donovan Jackson, whom his lawyer describes as developmentally disabled, became violent before the videotape begins.
But Saturday's incident, and the unusual videotaping, was enough to nudge some police officials out of their usual reticence to pass judgment on fellow officers.
