A woman has described to the Auckland High Court how she was shot in the leg before her husband wrestled with the gunman and she passed out.
Martin Victor Lyttelton, 57, has denied charges of attempted murder, causing grievous bodily harm and aggravated burglary.
Colleen Fenton told the Auckland High Court her husband had been business partners with Martin Lyttelton but their relationship broke down and they ended up court over a shareholding dispute.
Ms Fenton said she and her husband, Richard Ord, were at home looking at photos from a recent family wedding when she noticed Mr Lyttelton coming up the stairs holding a gun.
"I said, 'I'm not joking, Martin Lyttelton is in our house and he's got a gun. Dial 111 immediately'. All I could think about was getting the police there," Ms Fenton.
She closed the door and she and her husband put weight against it to stop Mr Lyttelton opening it.
"Well, there was this big thud that went into my leg … At the time I didn't know what had happened and then I looked down and saw this big red mass."
She said her husband wrestled with Mr Lyttelton and she passed out after hearing Mr Lyttelton tell her husband he had ruined his life.
Crown prosecutor Scott McColgan said Mr Lyttelton armed himself with the shotgun and a hunting knife that he bought just days before the incident.
"The Crown case is that Mr Lyttelton travelled to Mr Ord and Ms Fenton's home that morning with murder on his mind."
Mr McColgan said when Mr Lyttelton fired his gun, he did so at the very least to harm someone on the other side of the door.
He said during the later tussle with Mr Ord, Mr Lyttelton's gun went off a second time. He also drew a hunting knife but Mr Ord managed to hold Mr Lyttelton off until police arrived.
But Mr Lyttelton argued he had only gone to the Ord's home to harm himself.
"The defence case is that I was labouring under a major depressive illness and was in fact only intent on suicide when I went to the Ord's house.
"I had actually written a suicide note some two days before. My judgement was completely clouded by my mental illness."
He never intended to hurt Ms Fenton and apologised to the couple, he said.
The trial before Justice Asher and a jury was set down for three weeks, and would hear from 23 witnesses.