Thames Valley Police has launched a murder investigation after a former armed robber was killed following an assault by a gang of youths.
Eamonn Anderson, 56, of Salter Close, Oxford, was kicked off his bike in Oxford High Street on Tuesday, October 25.
Mr Anderson, who spent much of his life behind bars for a range of offences, was taken to hospital with serious head injuries, where he died on Friday night. His family has been informed.
He was cycling in High Street between 11.30 and 11.45pm when he was approached by a group of six young men, one of whom kicked him off his bicycle.
The group then left the scene, and witnesses contacted the ambulance service. Mr Anderson sustained serious head injuries
Mr Anderson spent 24 years in prison for armed robberies and firearms offences.
He once stole a ring which had belonged to Oscar Wilde from Magdalen College
In 2011 he started giving talks about his life where he turned to crime aged 13-years in a bid to prevent young people following in his footsteps and said judges should had down tougher sentences on armed robbers.
Shocked by some lenient sentences he said: "When people are getting seriously injured through violent crimes, they're traumatised for a period of time.
"Some people never get over it. They're physically or psychologically scarred for the rest of their life.
"I think people think it's acceptable to behave in a violent way, because of the way violence is portrayed in rap music, violent video games and there's a certain bravado about it.
"Today I see kids and young people being encouraged to do wrong things or become part of that gang sub-culture which exists.
"If they knew the reality of what lay ahead, they would think twice about having respect or admiration for crime, criminals or gangs."