A jury has heard covert recordings of an accused murderer telling an undercover police officer he committed a "crime of passion" by punching a man until he was unconscious.
Paul Anthony Quinlan has pleaded not guilty in Brisbane Supreme Court to the murder of Scott Pilton, 48, on May 16, 2020.
Mr Pilton died in hospital from acute bleeding on the brain just over a day after he was allegedly fatally wounded by Quinlan, then aged 55, on Lamb Island, north of Brisbane.
The jury on Thursday heard testimony from a senior constable in the Queensland police covert operations unit who spoke to Quinlan after he was arrested.
In response to questions from crown prosecutor Michael Lehane, the officer said he impersonated someone who had been arrested and was placed in a cell with Quinlan in the Brisbane Watchhouse on May 16, 2020.
The jury was played a 47-minute audio file that the officer had secretly recorded while pretending to have been arrested for assaulting his female partner over her adultery.
Quinlan in the audio said he had punched Mr Pilton a total of six times in the eyes, nose, mouth and cheekbone after catching him in bed with his then-girlfriend and dragging him to her lounge room.
"It was a crime of passion, like yours," Quinlan said in the audio.
The jury previously heard testimony from Quinlan's then-girlfriend Kimberly Lunt that the trio had been drinking at her house on May 14 before Quinlan and Mr Pilton argued over both men wanting to have sex with her.
Ms Lunt denied Pilton had got into bed with her while naked and also denied Mr Pilton had insulted her immediately before Quinlan had started punching.
In the audio, the undercover officer asked Quinlan what happened to his hand.
"I got stuck into someone," Quinlan said.
Quinlan at that time was facing an allegation of grievous bodily harm as Mr Pilton had been taken to hospital with brain injuries that would end his life later that day.
"You gave him a fair old touch-up?" the undercover officer said.
"Yeah. Knocked out ... unconscious," Quinlan said.
The officer asked Quinlan if he only punched Mr Pilton or also had kicked him.
"I think I did once or twice, I don't know. I lost my s*** ... there was blood on my right shoe," Quinlan said.
The officer later asked Quinlan if he put a "sneaky" kick with a running-shoe clad foot into Mr Pilton after knocking him to the ground.
"Up his nose ... I put my whole effort from the knee, just flicked it," Quinlan said.
The secretly recorded audio was at times unclear and the jury was provided with a transcript from the prosecution to help them keep track of the conversation.
Justice Peter Davis previously instructed jurors they should accept as evidence what they personally interpret from the audio if what they heard was different to what was written in the prosecution's transcript.
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