Donald Mackenzie, 38, lay in wait for Stuart Brown to return to his home in Lossiemouth, Moray, before launching the assault.

At the High Court in Edinburgh, judge Lord Arthurson stated: "You attacked a man in his own home in what was clearly a pre-planned attack."

Mackenzie's sentence will begin at the end of a 40-month jail term he is currently serving at HMP Barlinnie for drugs and weapons offences.

The attack happened on 6 July 2021.

Mackenzie pleaded guilty to assaulting Mr Brown by repeatedly striking him on the head with a hammer, seizing him by the head, and pushing his fingers into his eyes and struggling with him.

The court heard that Mr Brown later died but his death was unrelated to the attack by Mackenzie.

On the day of the assault, Mr Brown left his home to go to a shop before returning to the unlocked bungalow.

He went to his bedroom, but masked Mackenzie emerged from an en suite bathroom and launched the attack on his victim who was hit twice with the hammer.

During a struggle they moved into the hallway and Mr Brown managed to remove his attacker's mask and recognised his assailant as a local man.

At one stage Mackenzie was on top of him before the victim tried to calm him down and the attacker apologised.

Advocate depute Donald Davidson KC said: "He told the deceased he had to do it for the sake of his family."

When asked for the reason, he responded "he made me do it" but would not elaborate further.

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Mr Brown's lodger returned to the house and the victim claimed he fell off his bike.

Mackenzie left and Mr Brown asked the woman to stitch his wounds.

Nine days later, Mr Brown went to a hospital in Elgin, complaining of headaches and said he was unable to focus and was oversleeping. A CT scan came back clear.

Defence solicitor advocate Gary Miller said that at the time of the attack Mackenzie was "in the grip of a serious addiction" and ran up debt.

He said: "What led to his addiction was that he had a significant decline in his mental health."

Mr Miller said Mackenzie was overcome by "an attack of conscience" during the assault and stopped and apologised.

He said: "His conscience overcame him. He apologised to Mr Brown and thereafter tried to help him by wrapping a towel around his head to control the bleeding and offered to call the emergency services."