The family of a young man jailed for 19 years for a murder they say he didn't commit have appeared on a BBC documentary.

The family are filmed condemning the joint enterprise law that convicted their son of murder after a street fight in Ealing Broadway on August 6 last year left a 21-year-old dead.

Alex Henry, 21, of Homefarm Road, Hanwell was found guilty of stabbing to death Taqui Khezihi, also 21, despite him claiming to have never touched the knife.

Alex Henry

Alex was sentenced to life imprisonment in March using the controversial joint enterprise law which became the subject of an hour long documentary called Guilty by Association by Fran Robertson which was broadcast last night by the BBC.

Alex's mother Dr Sally Halsall and sister Charlotte featured heavily in the documentary which filmed the family as they prepared for the trial and eventually watched him convicted and sentenced in March this year.

Dr Halsall is filmed saying: "I just think they wanted to put them all in the frame. They know they were all there and as they are allowed to under joint enterprise they can just scoop them all up in one go. They do not have to find out which one of the four did it so it makes their job easier."

Guilty By Association starts with an opening speech about how it was the law of joint enterprise that eventually won popular convictions for the murder of Stephen Lawrence. The film goes on to explain that joint enterprise attempts to challenge the rising culture of gang violence in the UK. If multiple young men could be held responsible for the damage caused by the knife someone else was wielding, then gang membership might theoretically reduce.

The family of Ben Kinsella, a school boy stabbed to death by a gang of teenagers in Islington in 2009 were also interviewed in the documentary.

Ben's father George Kinsella said: "If it wasn't for joint enterprise those that had cornered our son, watched and encouraged as he was stabbed and then did nothing to help him as he bled to death would likely be walking the streets today. In five seconds he was stabbed 11 times and I hold them all responsible. If anyone disagrees with joint enterprise then they need to talk to the families of the victims of gang violence. Then they might change their mind."

A friend of Alex's, Cameron Ferguson, 20, of Ranelagh Road, Southall, pleaded guilty to murder and GBH on the fifth day of the trial. However this did not stop the jury convicting Alex and his other friend Janhelle Grant-Murray, 20, of Upfield Road, Hanwell of the murder.

His sister Charlotte said: "Cameron's actions on that day took Taqui's life away form him and left a family devastated. But this law has also taken two more victims. My brother and his friend Janel, who are now going to be serving life sentences for a murder they did not commit and two more families are devastated and two mothers hearts' broken. Something needs to change."

At the time of the sentencing of Alex investigating officer Detective Inspector Simon Deefholts, from the Homicide and Serious Crime Command, said: “This was a vicious attack sparked by nothing more than a trivial argument. Grant-Murray instigated a confrontation which erupted into violence when his associates, Henry and Ferguson - at least one of whom was armed with a knife - arrived at the scene."

In March this year the court heard that last August 6, the victim and his brother were with friends in Ealing before Grant-Murray came across them in Northcote Avenue. An argument began and the defendant was heard on the phone saying ‘bring a knife’ or ‘bring the knives’.

When the two other defendants approached, one or both of them were armed with knives and the three stabbed both Mr Khezihi and his brother in the back before running off.