Addressing an issue that I see raise its head from time to time, including recently on several forums. It is also a topic of primary interest for the martial artists in the self protection classes I teach: in fact, I think that LE does much better understanding the articulation of use of force, and is not well versed in the technical abilities to do so, and "civilian" martial artists tend to have more technical ability with little idea of how and when and to what extent they can act.
The misconception:
"Civilian use of force does not have to follow the same standard that law enforcement does. Civilian use of force can always immediately go to more dangerous techniques and tactics because the idea is not “arrest and control” but rather “self defense.” Therefore, “unlike police,” civilians can immediately use more violent means to defend themselves and are not bound by the same restrictions police are."
The Fact of the Matter:
For the martial artist who has at least some inkling of using his or her art in self defense, I must warn you that this is NOT TRUE. While you as a civilian are not required to restrain criminals who are attempting to escape, you also cannot use any level of force you desire against a perceived assault. You – just like a police officer – can only use force which is reasonable for the threat you can articulate.
Except in some misguided department policies (not by any means a national standard), police officers are also not required to use the minimal amount of force, or “not to harm” a suspect. The officer can use that force which he can reasonably articulate is necessary in the circumstances he faces. That may be high, that may be low. It is totally situationally based, to include what the individual officer and the individual assailant brings to the encounter.
“Civilians” are bound by the same standard. You simply must measure your self defense response in light of what you can reasonably articulate. In some states, you as a citizen may also have a duty to retreat (if you are not in your own home). Regardless, if an aggressive transient pushes you, you cannot gouge his eye out or attack his throat with a shuto if you cannot also give valid reasons for why you needed to do so. You cannot simply say “he *might* have pulled a knife” or “he *might* have had buddies attempt to surprise attack me” unless you can articulate the other various factors that would lead another person (as in the Jury) to the same conclusion. You simply do not get a “free ride” because you are accosted in the street or anywhere else.
Unless you have some rather questionable personal habits or hang with the wrong crowd, the majority of self defense situations will be nowhere near that violent. They will be relatively minor “aggressive transient” situations, bad attitude squabbles, or will be altercations/issues that are either domestic or otherwise involving people you know. Certainly any of these situations *could* develop to a point, or erupt at a point, that a high level of violent response is necessary, but that has to be supported by what you can reasonably conclude is about to happen, not by throwing everything and the kitchen sink into your justification for force because it could happen. You have some leeway there, just as does police use of force against violent threat (NOT arrest and control), but you do not have carte blanche to do whatever you want, especially if you are in fact over-reacting to the actual level of threat. Once again, you will not be held to the standard that an experienced officer will, but you could very well be held liable – even criminally - if you are perceived as over- reacting to a situation that was not in fact what you made it out to be.
More than one person has gone to prison because they severely injured someone in a garden variety push-and-shove that turned deadly based on their actions.