Self defence/ prevention of crime

Self defence/ prevention of crime

Under Criminal Justice and Immigration Act 2008, the first requirement for self defence/prevention of crime would be the use of "defensive force will only  lawful if it is necessary and it will only be necessary if it is used to resist,  repel or was off an unjust imminent threat,.  The act of self defence cannot be retaliatory or revengeful". An attack at some future will not be sufficient.

Mistake
If  self defence or prevention of crime arises from a mistake,  it must  be one which the defendant genuinely  believed.  Whether the degree of force is reasonable or not will be decided to circumstances as the defendant would believe to be (R v Williams).

- R v  O'Grady held that a defendant cannot rely on self defence where it results from a mistaken caused by his/her own intoxication.

The second requirement would be the self defence must be reasonable.  The defendant do not have a duty to retreat (R v Bird) or attack with proportionate force,  although the degree of force must be only necessary to repel an attack (R v Martin).

In circumstances  where defendant is the aggressor or deliberately provokes the victim,  there is no guaranteed right to rely of self defence (R v Keane).