Joint enterprise: Should gang pay for members' crimes?

The Supreme Court and Privy Council is to hear appeals in two cases where convictions were gained under the doctrine of joint enterprise.

It has become an effective way to prosecute murder, especially in cases involving gangs - but campaigners say it has led to 600 miscarriages of justice.

As reporter Jim Reed explains, it is controversial because there is no need to prove a member of the group intended to kill.