Mert Ney's family feared he was going to kill himself just days before he allegedly murdered a woman and went on a stabbing rampage, but police were unable to find him because of a monumental administrative blunder.
The accused attacker, 20, stormed through the CBD on Tuesday afternoon brandishing a large kitchen knife and soaked in blood.
Michaela Dunn, 24, was then found dead inside a Clarence Street apartment at 3.15pm, just over an hour after Ney allegedly stabbed Linda Bo, 41, in the back.
Those close to Ney say his 'steep descent into insanity' became so clear in the seven days leading up to the attack that police were trying to track him down.
But as police searched for him, they were unaware that Ney was living in government emergency housing and could easily have been located - potentially saving Miss Dunn's life.
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Michaela Dunn, 24, was found dead inside a Clarence Street apartment at 3.15pm, just over an hour after Ney allegedly stabbed Linda Bo, 41, in the back
While many were shocked by the alleged actions of 20-year-old Mert Ney (pictured), those close to Ney say his 'steep descent into insanity' became clear
Mert Ney is accused of killing a woman before running through the Sydney CBD with a large knife and stabbing another. He was restrained by civilians and firefighters using a crowbar, a chair and a crate (pictured)
It all began in the early hours of August 7, when Ney arrived at the Blacktown Hospital emergency department after suffering a prescription drug overdose.
Melinda Ettery, a patient in the emergency room, told the Seven Network it was clear he was agitated.
'He was loud and boisterous, being rude to nurses and doctors,' she said.
Hours later, he left the hospital and returned to his family home at Marayong in Sydney's west, where he allegedly launched a violent attack on one of his sisters.
The 20-year-old allegedly punched her in the face and choked her before she and her mother contacted police.
Ney fled before officers arrived, leading them on an urgent week-long hunt to find him, as they held fears he was going to kill himself, The Australian reported.
The sister, who declined to be named, said she wanted her brother to suffer for what he had done, and to be put in the worst (most severe) mental health institution to stop him from hurting anybody else
Stunned onlookers were frozen in the street as the man with a knife (pictured) began his rampage through the streets
Police Commissioner Mick Fuller today revealed that Ney had been reported missing before Tuesday's dramatic rampage on Clarence Street
Two days later, Ney went to a local GP and said he was having suicidal thoughts. The doctor contacted police - but he again avoided them.
In the three days before the rampage, Ney had been living in government emergency housing in Blacktown - but no one told the cops who were hunting him.
'Police were searching for him and we had concerns, but it's still a mystery to us why we didn't get a call,' a police source said.
According to The Daily Telegraph, it was the fault of Communities and Justice for not liaising with police or health authorities about Ney's potential danger.
A sex worker was later found with her throat slashed inside her central city apartment (Pictured, her neighbour's apartment)
Detectives believe he travelled into the city on Tuesday with the intention to 'kill and be killed by a cop's gun'.
It is believed he made an appointment with Ms Dunn for 1.30pm, but Ney only spent 20 minutes in her Clarence Street apartment.
Ney was seen on CCTV footage leaving the building at 1.50pm, and police allege he killed her before fleeing the block in a blood-soaked jumper and causing chaos through the streets of Sydney.
Investigators believe Ney and Ms Dunn had no prior contact before Tuesday but are looking through their phone records to determine the nature of their relationship.
'From our early investigations it appears the accused never had any intention of paying the victim for services that he had made arrangements for,'