Qld woman's murder a 'crime of passion'

A Queensland man shot his girlfriend in the head in a fit of jealous rage after realising their relationship was coming to an end, a court has heard.

Christopher Charles Koani, 31, is on trial in the Brisbane Supreme Court charged with murdering his girlfriend of six months Natalie Leaney, 26, at their Logan unit on March 10, 2013.

He pleaded not guilty to murder but guilty to the lesser charge of manslaughter at the start of the trial on Wednesday.

But Crown prosecutor Dennis Kinsella did not accept the plea.

In his opening address, Mr Kinsella said Koani intentionally shot his girlfriend with a shotgun in a "crime of passion" that was triggered by the realisation Ms Leaney was leaving him.

"There is no doubt that the accused, Christopher Koani, loved Natalie Leaney,", Mr Kinsella told the jury.

"The problem is that he loved her so much that not only did he take a loaded shotgun and point it at her, he then shot her in the head."

Mr Kinsella said there had been disharmony between the couple in the lead-up to the shooting and "the writing was on the wall".

Ms Leaney had confided to others that she was going to end the relationship.

On the day in question Koani locked her in their Rochedale South apartment during a bitter argument.

Two eye witnesses heard him tell Ms Leaney he "didn't give a f**k anymore" before he pointed a gun at her.

They heard a loud pop or bang and saw blood spray on the wall and heard Koani scream and call for help.

Police called to the scene found Ms Leaney slumped against the wall with a fatal shotgun wound to her temple, and Koani curled up on the ground and crying.

He told them she'd been shot by burglars but was charged with murder two days later.

The trial continues before Justice Jean Dalton.