Two brothers have each been jailed for 10 years for killing a man they thought had assaulted their mother.
Christopher and Robert Abraham, aged 26 and 20, attacked local football referee David Linning, 65, at his home in East Kilbride in Lanarkshire last December.
The assault happened after they received a text from their mother, who was in a relationship with Mr Linning, saying she had a "sore face".
The brothers later learned she had tripped and fallen while drunk.
Mr Linning was punched, kicked and slashed on the face with a knife during the attack.
His body was not found until two days later when a friend came to collect him to referee a football match in the town.
The brothers, who are the sons of former Radio Clyde presenter Mr Abie, were sentenced at the High Court in Edinburgh.
They had earlier admitted a charge of culpable homicide.
Judge Lady Stacey told them: "What you did that day was wicked.
"You went to the home of a man in his 60s when you were both fuelled by drink and, as you well know, drink is no excuse.
"You then proceeded to attack him. Two young men attacking an older man."
Lady Stacey noted that both Abraham brothers had expressed remorse but added: "No remorse you can now express can do anything to take away the anguish that Mr Linning's family - his large family - must feel because of what you did."
Speaking after the sentencing Mr Linning's son Billy, 37, said the family was relieved the case was over.
He added: "We would just like to say we are very happy with the outcome.
"It has been absolutely horrific. No two days are the same for any of us. Everyone is totally devastated and will be for many many years to come."
His son also told how Mr Linning, a dedicated volunteer with Alcoholics Anonymous, had been trying to help his killers overcome their problems with alcohol.
He said: "He was so helpful he was trying to help the two guys who killed him to get off the drink."
Mr Linning was a well-known figure around East Kilbride as a result of 30 years refereeing amateur football and hundreds of mourners attended his funeral.
In court defence lawyers described how the Abraham family had been blighted by alcohol and how at the time of the killing the brothers were homeless due to their drinking.
Defence QC Ian Duguid said if those involved had been sober, proper explanations could have been provided.
Lady Stacey said the brothers, who have a string of minor convictions, had been judged to be a high risk and made an order extending their licence conditions, after release, by two years.