Self Defence

D may rely on defence where

1. D honestly believed that circumstances exist which make it necessary to use force - subjective test

&

2. The force used by D is reasonable in the circumstnaces as believed by D - objective test

BOP - P must prive D's liability, so D did not believe in neccessity to use force or the force used by D was unreasonable

D honestly believed that circumstances exist which make it necessary to use force

R v Gladstone Williams (1984) - Honest belief even though it was a mistake 

Evidence of D's pyscological characteristics not revelant but pysical characteristics may be revelant 

Pre-emptive strike - D may act/use force if he honestly anticipates imminent attack

Beckford v R - Police officer called to a a house with an man armed with a shotgun so honestly believed he needed to use force to defend himself and others.

Where D provokes attack by V : Self Defence not available BUT where V responds to attack by D disproportionatley self defence may be available.

GP: D must use such force as is reasonable - objective

D's use of force only reasonable if proportionate to circumstances as percieved by D taking account of :

It may not be possible for D to 'weight to a nicety' the exact measure of necessary action

If D only did what he honestly and instinctlivey thought was necessary that's evidence that the force was reasonable 

Householder Cases:

Where a householder uses force to protect himself or others NOT property

- disproportioante force is NOT unreasonable

-grossly disproportionate force IS unreasonable

Necessity of Force:

IVI - where D honestly but mistakenly believes that it is necessary to use force in self-defence, D may rely on self-defence 

BUT: Where D's mistake is due to voluntary intoxication by D , D may not rely on self-defence