Nicholas Luke Martin, 30, has pleaded not guilty to murdering 42-year-old Shahn Baker as a NSW Supreme Court trial began on Monday.
He allegedly stabbed Mr Baker in the chest with a double-bladed knife during a dispute outside a social-housing estate in Erina, on the Central Coast, about 8.30pm on February 3, 2022.
An intoxicated Mr Baker went to Martin's home within the estate to look for his former girlfriend, Maxie Wilson, a jury was told during the prosecution's opening statement.
Ms Wilson had started a relationship with Martin several weeks earlier after a six-year relationship between her and Mr Baker ended, the court heard.
The jury was told they might hear evidence the relationship between Ms Wilson and Mr Baker was "unhealthy or toxic", including him once allegedly forcing her to drink bleach.
Before going to Martin's house, Mr Baker bought alcohol and was seen to be intoxicated by several witnesses, the jury heard.
Mr Baker told one witness Ms Wilson was still his girlfriend and he had bought an engagement ring with the intention of marrying her.
When he arrived at the house Martin shared with his grandfather, the two men had an altercation outside, the jury was told.
Ms Wilson is expected to give evidence she saw what she thought was Martin punching Mr Baker in the jaw.
Mr Baker then fell to the ground while Mr Martin remained with him, the court heard.
Following the incident, Martin and Ms Wilson allegedly lied to police about what occurred, telling them the stabber was an unknown man who fled the scene.
The jury could also consider a manslaughter verdict if they did not find Martin intended either to kill or seriously wound Mr Baker.
They would also have to consider the possibility of self-defence, which it was up to the crown to disprove, the court was told.
The trial continues.
18°C