Martin Carroll, 28, lost his temper after seeing a woman allow her dog to urinate in the tenement that they shared in Springburn, Glasgow, last year.
The High Court in Edinburgh heard yesterday that Carroll shouted at the woman because he has obsessive compulsive disorder (OCD). The court was told that Carroll was concerned about the potential risks to human health.
The dog owner’s friend, Stephen Gannon, 36, another neighbour, then confronted Carroll about his conduct towards her. An argument followed and the confrontation ended when Carroll repeatedly stabbed Mr Gannon in the neck with a knife.
Yesterday defence advocate Victoria Young told judge Lord Turnbull that her client suffered from OCD and anxiety. Speaking moments before her client received a life sentence, Ms Young added: “The matter related to dog fouling. Mr Carroll reacted more strongly to this than what the average person would have done.”
Carroll, of Springburn, Glasgow, had pleaded guilty at the High Court in Glasgow last month to murdering Mr Gannon on 14 August, 2015.
Sentence had been deferred on Carroll for the court to obtain reports. At earlier proceedings, prosecutor Ross McFarlane told the court that Mr Gannon lived downstairs from Carroll at the flats in St Monance Street.
The killer had a disagreement earlier in the year with another neighbour about her dog misbehaving.
On August 14, 2015, Mr Gannon was chatting to the dog owner, who wasn’t named, inside the tenement when Carroll walked by.
The court heard that Carroll was already wanted by the police at the time in connection with an attack on his mother.
Passing sentence, Lord Turnbull told Carroll that he would have to serve at least 14 years in custody before he could apply for parole.
He added: “Your release from custody is not a matter for this court. It is a matter for the parole board of Scotland.”