Miss Poli, a barmaid, grew up in Avondale but moved to Sydney several years before her death. She was found dead in her bed with a 20cm burn mark around her neck, leading police to believe she had been strangled with a piece of rope or cord.
After Mitchell's arrest the Herald revealed that Oscar-winning actress Cate Blanchett later lived in the Sydney bedroom where the murder took place.
Blanchett moved into the house and into Miss Poli's bedroom soon after the killing. She found out about the murder while watching Australia's Most Wanted.
She told Vogue magazine that she had to stay in the house as she could not afford to move elsewhere.
At the time of her death it was reported that a photo of Miss Poli with the head ripped off was found near her body.
A taskforce was set up to investigate Miss Poli's murder, and New South Wales police issued a warrant for the arrest of Mitchell - described as her de facto husband.
The Herald understands Miss Poli broke up with him and told him to leave their house shortly before she was killed.
Police believe Mitchell created a false identity to help him evade authorities.
Miss Poli's sister, Silk Sullivan, was only six when the murder happened.
"I don't remember specific details, but I remember the special cover up work they had to do with her because we had an open casket at the funeral. I just remember looking at her face for the last time," she said after news broke of Mitchell's arrest.
"I loved her very much. She was an amazing person, such a generous, loving person."
Ms Sullivan said it was frustrating knowing who had killed her sister, but being unable to find him.
She remembered spending time with Mitchell as a child.
"He was around, but I never thought anything was off or wrong with him."
She said over the years relatives had tried to find Mitchell themselves, without success.
