Greg Anderson brutally murdered his son with a cricket bat and a knife at cricket training in February this year before he was shot dead by police.
The Inquest heard from a policeman who said he thought Anderson was clever, calculating and bad, but didn't think he was mad. But his ex-partner Rosie Batty knew he had severe mental problems and was a serious threat to herself and her son.
Rosie Batty's legal team is up against barrister Dr Ian Freckelton QC, representing Victoria Police who said there were major differences of opinion between parties and questions had been raised about "fairness" and "independence."
The Inquest is supposed to end this week but Rosie Batty's team still has to call expert witnesses and there won't be enough time left for cross-examination. Hopefully, the Coroner will announce an extension tomorrow.
At the time of Luke Batty's death, a child protection file on him had been closed and there were a number of outstanding arrest warrants and AVOs in place against Anderson for his erratic, threatening behaviour.
He was in court on numerous occasions for harassing Rosie and their son but in June 2013, police let him go. He spent 12 days in custody and because he had no prior convictions and there was no evidence of physical injury, they let him out on bail.
Ms Batty gave police the address where Anderson could be found in the days leading up to the tragedy, but they decided not to act on it because it could make matters worse if he discovered she had told them where he was.
Senior Detective Cocking said he and his colleagues agreed that it was best to wait before they moved to arrest him and wanted to engineer a situation where it would appear police had come across him by accident.
Ms Batty gave police his new address on 5 February and on 13 February 2014, Anderson came to cricket practice - where parents and other boys were milling around - and bashed his son to death with a cricket bat.
He then came at police with a knife and shouted "shoot me." When capsicum foam failed to stop him and he lunged at officers with the knife, he was shot in the chest.
The tragedy is that if police had arrested him when Ms Batty gave them his address, her son could still be alive.
Police maintain they had no clue that Anderson intended to kill his son. "This was not an urgent matter" Senior Detective Cocking said.
The Inquest resumes today.