A man who murdered a good Samaritan in a knife attack has gone on the run from prison.
Police have asked the public to keep a look out for Brian Grady, who is also known as Brian Revill. They say he could be a danger and should not be approached.
Grady, 26, who was jailed for life in 2003, walked out of HMP Prescoed at Usk, in south Wales, on Monday and failed to return. The prison is a minimum-security establishment that usually houses inmates who have just a few months of their sentences to serve.
Gwent police believe Grady could be in the Bristol area, where he has family and other contacts.
A police spokesman said: "We have activated our operational plan with the aim of locating him, and the prison is co-operating fully with us.
"It is believed there may be a potential risk to the public due to the fact that he is no longer in the custody of the prison service."
Grady is described as white, 5ft 11in, of average build, with short, light brown hair and blue eyes. He has a scar under his left eye and speaks with a Bristol accent. He is not a registered sex offender.
Members of the public are being warned not to approach him but to call police if they have any information regarding his whereabouts.
Grady was jailed at Bristol crown court after being convicted of murder and robbery. He was part of a gang of teenagers who confronted a group of young people in Bristol in October 2002 and tried to steal a mobile phone.
Liam Attwell, a 25-year-old chef, saw what was happening and intervened but died after Grady, from the Barton Hill area of the city, stabbed him in the chest with a knife.
Sentencing Grady, who was then 17, Mr Justice Brian Keith said the murder had "left the city of Bristol in shock". He added that he believed the killing showed the danger of "immature boys" carrying knives.