A parliamentary inquiry has just started work into the law around Joint enterprise.

Joint enterprise is contentious because if a person is seen to be involved in a crime, from knowing about it, to egging someone on, being present, or even being able to predict that someone is likely to use a weapon like a gun - then they could be considered as guilty as the person who pulled the trigger.

It has a long history, but in recent times, it has been used as a way of prosecuting murder, especially in cases involving groups of people, when it's not known who carried out a killing.

But is it being applied fairly?

The CPS says “We choose the right charges for the right people based on the evidence in front of us. We look objectively at the evidence before making our own decisions.

and they add that “The CPS carefully monitors joint enterprise prosecutions, with senior legal oversight over every case to ensure that our approach is fair and proportionate.”

But campaigners say joint enterprise disproportionately results in working-class and black youths being prosecuted and convicted.

Presenter: Dr Joelle Grogan Producers: Ravi Naik, Arlene Gregorius and Bob Howard Editor Tara McDermott

Contributors: Alexander Hughes, Head Judicial Assistant at The Supreme Court "Cleeshay" who was convicted of murder under joint enterprise Jan Cunliffe, co-founder of Joint Enterprise Not Guilty by Association (JENGbA) Tracey Moloney, solicitor, Moloney family Law Dr Sam Fowles, a barrister and author David Duncan, solicitor and Director of the legal firm Duncan & McConnell in Dundee