A spurned lover accused of murder "saw red and attacked'', stabbing Darren John Booth and killing him in Kings Meadows last year, a Launceston jury has heard.
Michael Vernon Lowe, 52, who appeared in the Supreme Court in Launceston today, has pleaded not guilty to one count of murder on the basis of self defence,
In her opening statement, crown prosecutor Linda Mason said Mr Lowe went to the home of his former partner, Crystal Wells, and found Mr Booth there.
A violent struggle ensued between the two men and the accused stabbed Mr Booth three times in the chest, she said.
At one point the accused said ``I am the law'' while sitting on top of Mr Booth, she said.
After he left the Pinkard Street home Mr Lowe texted Ms Wells ``if you get the cops it won't be good'', Ms Mason said.
In a police interview Mr Lowe said he'd gone to ``sort things out'' with Ms Wells but was attacked by Mr Booth on arrival at the home.
He told police he responded with punches in self-defence.
The court heard he said he didn't have a knife and didn't know how Mr Booth came to be stabbed.
``Any citizen in our country ... is entitled to use such force ... necessary to defend themselves,'' defence counsel Greg Richardson said in his opening statement.
Mr Richardson said the crown had to prove his client was not acting in self-defence.
If self-defence was disproved the jury then had to consider `the state of mind of Michael Lowe at the relevant time''.