A man accused of murdering his brother-in-law and attempting to murder his wife and two other people said he stabbed her in a “moment of madness” after reading text messages she sent her boss saying she was going to leave him, a court has heard.

The High Court in Edinburgh was told on Thursday that in a police interview, Finlay MacDonald said after stabbing his wife in the kitchen of their home on Skye he felt a “total darkness come over me”.

He said he then got into his car with a shotgun and a “machete-type knife” before carrying out the other alleged attacks, jurors heard.

His eight-year-old daughter came outside just as he was leaving, and as he drove off he could see his injured wife “lying down on the ground” outside, he said in the interview.

MacDonald, 41, is on trial accused of murdering his brother-in-law John MacKinnon on August 10, 2022 by repeatedly discharging a shotgun at him in the village of Teangue on Skye.

He is accused of firing a shotgun at married couple Fay and John MacKenzie and attempting to murder them in the village of Dornie, Wester Ross, on the same day.

He is also accused of attempting to murder his wife, Rowena, by repeatedly stabbing her in the village of Tarskavaig, on Skye’s Sleat peninsula, also on August 10.

In addition, MacDonald faces a charge of possession of a shotgun “with intent by means thereof to endanger life”.

He denies all the charges against him.

On Thursday, the court was shown footage of a police interview with MacDonald at an Inverness police station the day after the alleged attacks.

In it, MacDonald, draped with what appeared to be a blue blanket, explained his life had been on a “downward spiral” in the months leading up to the incident.

He said he was suffering from a number of physical problems that left him in pain and unable to work, including a lung condition and a displaced bone in his chest.

He added that when he went for osteopathy treatment from Mr MacKenzie, he was “subjected to a brutal manipulation” which left him in “chronic pain”.

He said this left him with spinal problems that he felt had “taken (his) life chances away”.

MacDonald also told police how his marriage suffered as a result of his deteriorating mental and physical health.

He said his wife “resented” his health conditions and became cold towards him, and that she had told him she did not love him any more.

This came to a head, he said, on the morning of August 10, when after becoming “suspicious” he looked at his wife’s phone and saw text messages between her and her boss in which she said she was going to leave MacDonald.

He said after confronting his wife about the messages, she tried to grab his phone, which had pictures of the text messages, and that the pair “wrestled” before he stabbed her with a knife he had been using for whittling wood.

“I just had a moment of madness and then I realised what I had done and I just broke down,” he said in the interview.

He explained he “didn’t know what I was going to do” when he got into his car with a shotgun, “a couple of hundred” cartridges and a knife, but that he began thinking about grievances with his brother-in-law and osteopath.

The court heard he told police he first drove to Mr McKinnon’s house, where he “confronted him and said he had bullied me and he is horrible to me”.

He said his brother-in-law “came towards me” and he shot him twice, once in the front and once in the side.

He said he then drove the 10-15 miles to Mr MacKenzie’s house, and that he fired through the window when nobody appeared to be there.

MacDonald told police Mr MacKenzie then came out of the house, and that the pair went into the kitchen where they began “wrestling” for the gun, before it “went off”, the court heard.

He said he next remembered being tasered by police, who the court earlier heard had followed him to Mr MacKenzie’s house.

The 41-year-old said to officers: “I never started the day with the intention of doing anything other than try and save my marriage.

“I didn’t want to do any of it.

“I wasn’t the person I normally am. It all just went to madness.

“Something went off in my head and I just felt like I had become someone else.”

The court also heard on Thursday from forensic psychiatrist Dr Alastair Morris, who carried out a detailed examination of MacDonald’s medical records and spoke to him in person for more than two-and-a-half hours at HMP Grampian.

The doctor concluded MacDonald had been suffering from post-traumatic stress disorder, depressive disorder, and autistic spectrum disorder, but said in his opinion the 41-year-old did not have a “specific personality disorder”.

MacDonald has lodged a special defence against the murder charge, claiming his “ability to determine or control his conduct was substantially impaired by reason of abnormality of mind”, and a judge said he could be convicted of an alternative charge of culpable homicide if the jury believed his defence of diminished responsibility.

The trial continues in front of Judge Lady Drummond.