A Good Samaritan who handed a lost handbag into a police station was murdered by having his throat slit after he was mistakenly accused of stealing it.

Frederick McGettigan had done his “civic duty” by giving the item to officers when he discovered it beside a canal in July last year.

But Kirk McIntyre later turned up at the 51-year-old’s flat in Auchinairn, Glasgow, wrongly believing Mr McGettigan had taken the bag from the house of someone he knew.

McIntyre then attacked his frail victim and slit his throat with a knife.

McIntyre denied murder during a trial at the High Court in Glasgow, but jurors heard he had once confessed to having done “something bad”.

He has now been jailed for life and ordered to serve a minimum of 20 years following his conviction on Tuesday.

It emerged he already had a long history of violence and had recently been freed having previously been jailed for a serious assault.

A judge told McIntyre, of Perth, that the killing of Mr McGettigan was “barbaric and cruel”.

The trial heard how Mr McGettigan, known as Ricky, had found the bag at the Forth and Clyde canal in Kirkintilloch, East Dunbartonshire.

The discovery came during an early-hours walk that Mr McGettigan would often take as he suffered from the ear condition tinnitus. Mr McGettigan then handed the bag into the local police station.

But days later, on August 6, McIntyre suddenly appeared at his door in a fury before brutally attacking his victim with a blade and leaving him for dead.

The alarm was later raised after a friend of Mr McGettigan became concerned when he could not contact him.

The court heard William Elliot eventually went to his flat on August 9, where he found Mr McGettigan’s body.

Describing the scene, he recalled: “I got no answer then opened the letterbox and shouted through.

“I realised then the door was unlocked. There was blood on the hall carpet. I looked in the kitchen and saw Ricky lying on his back.”

He added: “His face and hair was covered in blood. I took my phone out and dialled 999.”

The trial heard McIntyre later met a social worker and admitted he had done “something bad” and that it was “high court level”.

In his speech to jurors, prosecutor Iain McSporran, QC, said: “He was not just confessing to a crime – he was confessing to this crime.”

He added Mr McGettigan died “as a result of doing his civic duty” by going to police with the bag.

After the verdict, the court was told McIntyre had 16 previous assault convictions.

Lord Mulholland told McIntyre: “He was a man who had done you no harm.

“You sought him out believing he was responsible. He was not responsible and had merely handed in the bag as any good citizen would do.

“What you did was barbaric and cruel. You slit his neck and left him to his fate.”