In October, 1997, Anu Singh, 25, killed her boyfriend Joe Cinque after lacing his coffee with Rohypnol and giving him a lethal dose of heroin.
The law student planned a suicide pact between her and her partner, but Joe was completely unaware of the scheme.
She even planned two farewell dinners with friends where she told them of her suicide pact – but no-one told Joe.
Anu stood by Joe’s bedside for 36 hours and watched him slowly die in their Canberra home. The case still baffles Australia decades on.
Now, the 44-year-old will speak out about the crime for the first time on television on Sunday Night. She hopes her interview will help Joe’s parents, Maria and Nino, forgive her.
“There are many things people don’t understand,” she says. “I’d love to turn back the clock.”
In an interview with News Corp, Anu says she was "mentally unwell" at the time she killed Joe.
“There’s no rational motivation at all. I was mentally unwell, and I still grapple with that. I still grapple with the whys,” she said.
“One of the psychiatrists mentioned a state of disassociation, perhaps, like disassociated from reality. I don’t know. There’s no rational explanation.”
She was found guilty of manslaughter and sentenced to 10 years in jail due to ‘diminished responsibility’.
Watch Anu’s interview on Sunday Night 8:30pm on Channel 7.