It's been more than three years since Teah Rose Luckwell, 22, was found dead by neighbours on the kitchen floor of her South Tamworth unit.
At the time, her one-year-old daughter was also in the house unharmed but covered in blood.
Jesse Leigh Green, 30, was charged with Teah's murder this week by the New South Wales Supreme Court in Sydney, and two other offences including break and enter and using an offensive weapon.
He has also been found not criminally responsible for all counts.
In the special hearing on Monday, two psychology experts deemed Mr Green suffered from schizophrenia, which had arisen in his late teenage years.
Prosecutors said Ms Luckwell was stabbed three times with a knife on March 28, 2018.
One wound to an artery in her neck became fatal.
The Supreme Court has been told an ambulance officer called to the unit around 10pm found her body in a pool of congealed blood, indicating it had been there for several hours.
No defence wounds were found on Ms Luckwell's hands or arms.
The defence prosecutor told the court this was not consistent with a "creep gone wrong".
However, Supreme Court Justice Stephen Campbell held another scenario.
"Probably she turned on the light when she went to investigate a noise or other disturbance at her front door," Justice Campbell said.
"Such a scenario would account for her location in the kitchen and would not require any particular motive on the part of Mr Green other than to avoid detection and get away."
Screams heard and a man seen running
Witness Donna Searle, who lived two doors from the crime scene, said she heard a single scream she would "never forget".
Ms Searle told the court that she woke around 3am and was lying awake reading.
As she lay awake, one of her three cross Maltese-terrier dogs growled "a weird sort of growl".
When she looked out the window she saw what appeared to be a young guy running and had some issues with moving.
"To me, that staggering movement is consistent with what I have already said about Mr Green's mode of movement as depicted on CCTV footage," Justice Campbell told the court.
Previous grievances unrelated to stabbing
Mr Green lived in the units behind Ms Luckwell and had previous contact in the lead up to her death.
The court heard that Ms Luckwell made several complaints about Mr Green when applying for a social housing transfer in October 2017.
They included leaving needles, broken glass, and bouncing a basketball at late hours of the night.
The transfer and complaint were never followed through as Mr Green moved residence later that month.
Appearing by video in September this year, witness Casey-Louise Stace also told the court she knew Mr Green often talked about her.
Despite their previous contact, Justice Campbell said it made no suggestion that Mr Green harboured any resentment or other harmful attitude towards Ms Luckwell.
Mr Green will remain in detention under supervision until he is deemed fit for release.
