This sums it up nicely. It gets subjective though when you start trying to define what is "reasonable force" in each situation.
Not really. Under our laws (UK) as long as you use common sense you can even use lethal force, it has to be violence appropriate to the situation. If you are attacked by an armed person, whether it's a gun or another weapon and you are in fear of your life ( obviously) you can use lethal force, you can even use a pre-emptive strike. If you successfully fight off an attacker using 'strong' force because you are in fear of your life or fear for others that's fine. What is not fine is fighting off an attacker, putting him/her down then kicking them in the head, disproportionate force. If someone throws a punch at you and you take a weapon of some sort and beat him up that is not fine. Defending yourself is good but going over the top is not.
This is UK law.
"
Reasonable Force
A person may use such force as is reasonable in the circumstances for the purposes of:
- self-defence; or
- defence of another; or
- defence of property; or
- prevention of crime; or
- lawful arrest.
In assessing the reasonableness of the force used, prosecutors should ask two questions:
- was the use of force necessary in the circumstances, i.e. Was there a need for any force at all? and
- was the force used reasonable in the circumstances?
The courts have indicated that both questions are to answered on the basis of the facts as the accused honestly believed them to be (
R v Williams (G) 78 Cr App R 276), (
R. v Oatbridge, 94 Cr App R 367).
To that extent it is a subjective test. There is, however, an objective element to the test. The jury must then go on to ask themselves whether, on the basis of the facts as the accused believed them to be, a reasonable person would regard the force used as reasonable or excessive.
It is important to bear in mind when assessing whether the force used was reasonable the words of Lord Morris in (
Palmer v R 1971 AC 814);
"If there has been an attack so that self defence is reasonably necessary, it will be recognised that a person defending himself cannot weigh to a nicety the exact measure of his defensive action. If the jury thought that that in a moment of unexpected anguish a person attacked had only done what he honestly and instinctively thought necessary, that would be the most potent evidence that only reasonable defensive action had been taken ..."
The fact that an act was considered necessary does not mean that the resulting action was reasonable: (R v Clegg 1995 1 AC 482 HL). Where it is alleged that a person acted to defend himself/herself from violence, the extent to which the action taken was necessary will, of course, be integral to the reasonableness of the force used.
In (R v OGrady 85 Cr App R 315), it was held by the Court of Appeal that a defendant was not entitled to rely, so far as self-defence is concerned, upon a mistake of fact which had been induced by voluntary intoxication.