Luke Batty inquest: Police officer 'astounded' Greg Anderson was granted bail before killing

A police officer involved with the family violence case between Rosie Batty and her former partner Greg Anderson says he was "astounded" Anderson was released on bail before he killed their son.

Anderson murdered 11-year-old Luke Batty at the Tyabb cricket ground in February before he was shot dead by police.

At the coronial inquest into Luke's death, Ms Batty accused authorities of not doing enough to protect her son. She broke down repeatedly while giving evidence earlier this week.

Senior Constable Paul Topham told the inquest on Thursday he had "a large number" of conversations with Ms Batty in the year before Anderson killed Luke and was aware Anderson consistently failed to turn up to court hearings about their son.

Senior Constable Topham said he believed Anderson was highly intelligent and knew how to work the system.

He arrested Anderson in January 2013 and a video recording of Anderson's police interview with him was played to the court, in which Anderson appeared aggressive and refused to answer questions.

"You've got nothing... I wish to leave," Anderson can be seen saying to Senior Constable Topham.

Senior Constable Topham said he considered Anderson violent and dangerous and wrote at the time that Anderson was "nuts".

"Anderson was probably one of the ones that worried me more than the other guys," Senior Constable Topham said.

"The first time I arrested him he became extremely aggressive and I took my OC spray out.

"He was in control of the situation... he was smart enough to shut it down before it got to the next level."

Anderson was never diagnosed with mental illness and Senior Constable Topham told the inquest he saw no signs of mental instability.

"Without a question in my mind, as we say, he was 100 per cent bad... not mad.

"His demeanour... he had no regards for authority whatsoever... whatever we did for this guy, he didn't care.

"He knew what he was doing."

Anderson 'knew how to play the system'

Senior Constable Topham said after Anderson was arrested on child pornography charges and appeared in court he was "astounded" when Anderson was granted bail, as Luke's father could not provide a stable address.

Anderson was bailed to a motel.

Senior Constable Topham said it was a common, continuing problem for offenders with no fixed address.

"I was particularly unhappy with that... we knew it was a marginal address that he'd disappear from after a few days," he said.

"I was astounded that he still got bail based on the information that we had."

Senior Constable Topham said he later found out Anderson had changed his address to his car at the earliest opportunity and was unable to be tracked down.

He also told the inquest Anderson knew if he did not turn up to court hearings his bail would be revoked, an arrest warrant would go out, and he no longer had to report to police.

"He knew there was a glitch [in the system]," Senior Constable Topham said.

"He knew once the warrant is out, 'I don't have to report'. What do we do with a guy like this... the writing's on the wall, but he has no criminal record and no recorded mental illness.

"We've gone down the psychiatric path... it didn't work. We've gone through the courts... it didn't work. The courts let him out."

Senior Constable Topham said when he arrived at Tyabb cricket ground on the day Luke was murdered by his father, he could hear screaming.

"I realised it was Rosie Batty," he said.

The inquest continues.