law fairer, but some murder victims' relatives said they were worried about possible appeals.

From duelling to gangs

Image caption Gary Dobson and David Norris were convicted under joint enterprise of the 1993 murder of Stephen Lawrence

Joint enterprise law was originally used to stop aristocrats from duelling, allowing all those involved in the duel, including doctors, to be charged with murder along with the duellists.

The law is regarded as a vital prosecuting tool and was used to convict David Norris and Gary Dobson in 2012 for the 1993 murder of Stephen Lawrence.

However, in February the Supreme Court ruled that the courts "took a wrong turn" in 1984 in their interpretation of the law.

This judgement referred to a ruling in a case in which three gang members armed with knives burstinto the home of a prostitute and her husband in Hong Kong, intending to collect a debt.

The husband was stabbed to death at the hand of at least one of the gang members and all three were convicted of murder.

In February judges said the error made had been "to equate foresight with intent to assist, as a matter of law; the correct approach is to treat it as evidence of intent".