Murder accused admits to party stabbing

Ashley James Gunson stabbed a partygoer in the heart until the scissors could go no further, but he did it in self-defence, a Perth court has heard.

Gunson, 24, is on trial in the West Australian Supreme Court charged with the murder of Jamie Devine, 20, and the unlawful wounding of Karl Viandante and Brodie Browns.

Mr Devine died in hospital on January 11 after being stabbed at his cousin's 21st birthday party in Atwell.

The court heard on Monday the party was winding down when a melee broke out.

Gunson admits fatally stabbing Mr Devine with scissors during the brawl, but claims he acted in self-defence.

He denies stabbing Mr Viandante and Mr Browns, who suffered serious wounds to their arms.

Prosecutor Amanda Forrester said in her opening statement the entire length of the scissors penetrated Mr Devine's chest, piercing his heart.

Ms Forrester said Gunson then fled the party but was chased by a group of people who assaulted him.

She said police found Gunson's clothes half-burnt in a bucket at his home.

Defence lawyer John Bougher said alcohol, drugs, fatigue and poor lighting severely limited the ability of witnesses to give evidence about the night.

Mr Bougher said Gunson did not intend to kill Mr Devine, and DNA found on the scissors showed other people had held them.

The trial continues.