In the days after 66-year-old Doris Fenbow was raped and murdered in her Sydney flat, police interviewed her teenage killer and noted he "heard or saw nothing that could assist".
Now, more than 27 years later, he has been found guilty of both crimes.
Ms Fenbow's body was discovered amid billowing smoke, lying in her flat in Sydney's southeast on the morning of September 3, 1988.
Her feet and legs were charred, she was naked from the waist down and she had bruising to her eyes.
Retired policeman Robert Checkley told the Supreme Court this month how long spiderwebs were hanging from the ceiling when he arrived at Ms Fenbow's untidy flat.
Her body was slightly burnt on her lower right side and cushions had been placed against her and stacked underneath her and set alight.
Paper on the floor looked like it had been used to set a fire.
Three days after her death, then police officer Martyn Downs interviewed Ms Fenbow's neighbour, the then 17-year-old, who can only be referred to as BL.
Reading from notes made at the time, Mr Downs said "BL heard or saw nothing that could assist with the murder of Doris Fenbow".
For years, the person responsible seemingly remained a mystery.
A 1989 inquest and an extensive police investigation failed to lead to any arrests.
But after Unsolved Homicide Team relaunched investigations, BL was charged last year.
His trial heard how a sample given by him in 2014 was compared to DNA found on Ms Fenbow, and that the profile occurred only once in every 100 billion people in a theoretical population.
In mounting his defence, BL did not dispute the DNA results or that he had sexual intercourse with Ms Fenbow.
But he said he had been forced upon her by a man who had been sexually abusing him throughout his childhood - the now deceased Kevin Hayward.
On the evening of September 2, BL claimed he had gone out to get cigarettes when he was punched by Mr Hayward and dragged into a darkened unit.
Once there he says he was sexually assaulted by Mr Hayward and forced on top of Ms Fenbow's body.
While the defence conceded the account was "extraordinary", they said BL had nothing to do with her death.
The crown, however, said there was no other male DNA found in the flat but BL's.
On the night of September 2, they said he had gone out drinking with his sister and her friend before returning home about 2.30am.
It was sometime between then and 7.50am that they said BL - just a week shy of his 18th birthday - raped the 66-year-old in her flat, where she lived alone.
In a bid to cover up the crime, the crown said he decided to kill her by a combination of beating, strangulation and fire.
After almost two days of deliberations, the jury on Wednesday found him guilty of both counts.
He will return to court next month for sentencing.
