Alleged murderer said mate became 'demon'

Mathew Flame told police he was
Mathew Flame told police he was "possessed" after taking more and more ectasy and cannabis.

The man accused of murdering his best friend, Liam Anderson, rambled about Satan before telling police "I was possessed last night" and asking "is someone dead because of me?"

"You wouldn't believe what happened last night ... I need a f***ing lawyer," Mathew Flame also said in recordings played to the NSW Supreme Court jury on Thursday.

The 22-year-old apprentice plumber has pleaded not guilty by reason of mental impairment to the bashing murder of Mr Anderson, the son of Angry Anderson, singer with hard rock band Rose Tattoo.

An American tourist has testified to seeing an emotionless assailant repeatedly stomping on the bloodied head of his victim shortly after sunrise on November 4, 2018 in a Queenscliff park on Sydney's northern beaches.

The Crown contends Flame was psychotic at the time due to his voluntary use of drugs including ecstasy, while the defence says he was labouring under the severe mental illness of schizophrenia.

Constable John Kennedy told the jury Flame was brought into Manly police station at about 7.10 am when he constantly rambled about Satan.

"You have no right to keep me here says Satan, I am innocent, you deserve torture," Flame said.

"You lied to Satan, you can't disobey Satan. He is not happy you are doing this especially to Mathew Flame."

He told the constable: "Man you would not believe my night, are you seriously a real person?"

In the later recordings when he seemed more coherent, Flame said he had taken ecstasy and cannabis.

"I kept taking more and more and more and it went into a psychiatric trip or something," he said.

"I was f***ing possessed last night, man, I'm not even kidding.

"It may sound f***ing crazy, I don't even know how to explain it right now, man, I was in hell last night."

"Some form of entity that took over me" and "my mate actually had the demon inside him", and apparently "was really angry with me" and "it wanted me dead".

His friend Liam kept talking back to him and "I was under his control".

"It may sound crazy, seriously, but the drugs affected me in a certain way and it took me somewhere."

He later said he knew he had hurt somebody, asking "is someone dead because of me, man?"

"Mate, we just got to let detectives talk to you about that kind of stuff," the constable replied.

When paramedics were called after Flame's heart was racing he told them he had taken "10 tablets of MDMA and punched some cones of cannabis".

He also replied "no" when police asked if he had a history of mental illness.

The trial is continuing before Justice Richard Button.

Australian Associated Press