Alan Pemberton had been devastated over a bitter divorce battle, and had previously threatened to kill his estranged wife Julia, before arriving at the family home in Hermitage armed with a shotgun last November.

In the attack, Mrs Pemberton hid in a cupboard and dialled 999, while her son Will spoke to Mr Pemberton outside the £1m mansion in Slanting Hill.

Armed police were despatched but by the time they arrived, both the 47-year-old mother and her 17-year-old son had been shot, and Mr Pemberton, 48, had also taken his own life.

The inquest jury heard how Mrs Pemberton had refused to move to a safe house after he was banned by a court from going near the house. Family members also told how she became convinced he would be back to kill her.

Mr Pemberton had been spotted at the Parasampia Golf Club on the afternoon of the attack, before approaching the house at 7pm. Neighbours heard shots from the Pemberton’s house, and police arriving on the scene found Mr Pemberton’s BMW parked nearby, with an explanatory note inside a briefcase.

Recording a verdict of unlawful killing, coroner Peter Bedford said Mr Pemberton was a ‘man with a plan’ who had become embittered over the loss of his wife, his business and his house.