Dale Wickham, 62, admits shooting dead her husband John only minutes after calling police to her West Auckland home in October last year.
The case is being heard in the High Court at Auckland.
Wickham has pleaded not guilty and her lawyers argue the shooting was in self-defence.
Her lawyer, Sanjay Patel, told the jury today that Mrs Wickham, who has multiple sclerosis, had heard from a friend that her husband had discussed helping her to commit suicide.
“But the worrying thing about that is that Dale and John never discussed it,” Mr Patel said.
He said there was an escalating “climate of fear” at the couple’s home with arguments that had turned violent in the past.
Mr Patel said Mrs Wickham had called police to the house before and on October 10 last year she was pushed over and threatened.
Mr Patel quoted Mr Wickham saying: “I’ll gut you like a fish”, before Mrs Wickham pulled the trigger and shot her husband dead.
He told the jury that Mrs Wickham was a frail woman who had no ability to protect herself and shot her husband in self-defence.
Crown prosecutor Ross Burns told the jury that Mrs Wickham could have locked herself in her ensuite and waited for police to arrive.
“She could have sat on the toilet seat with the loaded gun, the door locked, and said: ‘If you come in, I’ll blow your head off’.”
He said Mrs Wickham kept a loaded gun under her bed and had armed herself with a hammer and a knife in the days leading up to the shooting
“She obviously collected these for a situation where she was prepared to use them if necessary,” Mr Burns said.
He said Mrs Wickham had found a half-used packet of the erectile dysfunction drug Cialis, only months before she shot her husband and had only chosen to tell friends and family members days before October 10.
“Maybe she was angry, she fears that this man was about to leave her to her own devices,” Mr Burns said.
Yesterday, the court heard that Mrs Wickham called police to her home after her husband grabbed her around the throat, months before she killed him with a shotgun blast to the chest.
The Wickhams were married for 40 years but evidence read at court yesterday showed Mr Wickham planned to separate and had drawn up an agreement between him and his wife in the year he was shot dead.
Two police officers were called to the Wickham home in Massey on New Year’s Day last year after Dale Wickham found $8000 in a file. She said she was preparing lunch when her husband grabbed her around the throat and the pair fell to the kitchen floor.
Mrs Wickham told Constable Hayley Kenna she had “no muscle” and could not fight back.
Constable Ian Carter said he spoke to Mr Wickham at the same time in a separate room.
He said Mr Wickham told him he had slipped on the kitchen floor and put his arms out, dragging his wife to the floor.
Mr Carter said he asked Mr Wickham if he had grabbed his wife’s neck and Mr Wickham said his hands “must have gone around her somewhere”.
“She declined to make any complaint and she was adamant that she did not want John Wickham removed or charged,” Mr Carter said.
He said Wickham asked him if he could see marks on her throat.
“I said: Yes, but I’ve also seen you rubbing your neck,” Mr Carter said.
Under cross-examination from Michelle Wilkinson-Smith, Mr Carter confirmed that Wickham’s rubbing of her throat was consistent with her having a throat injury.
“If someone wanted to fake marks on their neck, they wouldn’t do it in front of a police officer?” Ms Wilkinson-Smith asked. Mr Carter said: “No, you would not”.
Mr Patel, told the jury that the defence case was based on self-defence.
“You will need to step into the shoes of Mrs Wickham and judge it in her eyes and to do that, you will need to labour under the physical debilitations that she was under at the time.”
Mr Patel introduced Stephen Robinson, a neighbour of the Wickhams, who said he was on his way to buy milk three days before the killing when he saw Mr Wickham take a shotgun out of his red van and into the garage of the couple’s Massey home.