The killer of Angry Anderson's son could be released within four years after demonic beliefs and drug-induced psychosis led him to beat his best mate to death.
Mathew Flame, now 22, was suffering an acute psychotic episode when he beat and kicked Liam Anderson to death in a park on Sydney's northern beaches about sunrise on November 4, 2018.
Mr Anderson, 26, left a friend's nearby home in pursuit of his psychologically distressed best mate before he was set upon.
"His final ordeal was extended, gruelling, terrifying and horrifically painful," NSW Supreme Court Justice Richard Button said.
The psychotic episode had been sparked after Flame, who'd been partying all night with Mr Anderson and other friends, took a 10th MDMA capsule about 5am.
After his friend caught up, Flame hit him with fists, feet and possibly a large rock found at the scene, Justice Button said.
"Even accepting he could see with his eyes the appearance of his friend, I accept he believed the recipient of his actions was demonic," Justice Button said.
"There was never the desire to bring to an end the life of a human, let alone a close friend."
Justice Button, noting the case cried out for a finding of special circumstances, jailed Flame for a minimum of five years and six months.
His full sentence of eight years will expire in November 2026.
Gary "Angry" Anderson, who fronted rock band Rose Tattoo for decades, watched the sentence from a balcony in the courtroom.
"Two years ago, our Liam had his life taken - his life," Mr Anderson told reporters outside court on Wednesday.
"Two years ago, our family and those who love him started a lifetime sentence."
During his trial this year, Flame pleaded not guilty to murder on the grounds of mental illness before a jury found him guilty of manslaughter due to the effect of the psychosis.
While in custody, he developed the chronic and severe mental illness of schizophrenia, for which he now takes medication.
Flame was still psychotic when confronted by police, believing they too were demons, and was frothing at the mouth while in custody.
But the realisation of his action set in hours later and Justice Button was firmly of the view Flame was deeply remorseful and bitterly regretted what he had done - far beyond mere self-pity.
