Currently, duress (when you are forced to commit a crime) will result in a complete acquittal for all criminal offences except murder (or any offence involving murder - attempted murder, participation to murder etc) . To best illustrate the scenario, I'll use a simple example:
Joe points a gun at Bob's head, telling him that if Bob does not murder Harry then Joe will shoot and kill Bob. Bob obliges, and sure enough he kills Harry.
Now I don't think Bob should be guilty of murder, but the law says he is. Should people be expected to 'be a hero' and sacrifice their life over somebody else's?
I think the defendant should be acquitted because:
1. The law should not expect people to be heroes.
2. The duress defence always bangs on about how the defendant should always choose the lesser of two evils. Well, sometimes killing someone is the lesser of two evils.
3. Although they say in special circumstances the CPS will decide not to prosecute, I believe this is an unsatisfactory substitute for a clear and fair law.
4. People who are against duress being a murder defence claim that the defence is too easy to raise and difficult to disprove, but that's just like every other defence anyway!