Hundreds of convictions could be challenged after the ruling on the law - which can result in people being convicted of assault or murder even if they did not strike the blow.
Justices said prosecutors, judges and jurors had to take a different approach when dealing with defendants accused of being involved in joint enterprise crimes.
Former barrister and Catholic writer Maureen Mullally-Clarke said: "As a Christian lawyer I can say it is a triumph for justice".
She added: "From a Christian point of view it is extremely sad that there are people in prison who are innocent of the crimes of which they've been convicted.
"There's no doubt about it, there are some people in prison who shouldn't be."
The Supreme Court said it was not right that someone should be guilty merely because they foresaw that a co-accused might commit a crime.
The racist murderers of black teenager Stephen Lawrence and three teenagers who beat Warrington father Garry Newlove to death in front of his children are among high profile killers jailed under joint enterprise laws.
It is also used in cases where a victim or victims dies as a result of an attack by more than one person and it is not clear which of them caused the fatal injury.
Ms Mullally-Clarke added the ruling means "the test will be whether the person had intention to assist and encourage."
Joint enterprise "has been unfair" she said on Premier's News Hour.
"It is not lightly that the Supreme Court overturns decisions of the Court of Appeal that have stood for 30 years."
A group campaigning for a change in the law on joint enterprise said the ruling was a "major turning point" and said hundreds of people could be affected.
Maureen Mullally-Clarke speaking to Premier's Antony Bushfield: