An "evil" John Travolta fantasist faces spending the rest of his life behind bars for the brutal rape and murder of a teenage girl 34 years ago.
For half a lifetime, self-employed tiler James Warnock, 56, evaded justice for strangling 17-year-old Yiannoulla Yianni in her own home, just half a mile from where he lived.
The murder shocked the nation and led to high-profile police appeals, with detectives travelling as far afield as Australia in their search for the killer.
But it was not until December last year that Scotland Yard got a "lucky break" after Warnock was caught sharing indecent pictures of children with an undercover officer online.
His DNA was added to the national database and found to be a match for samples taken from Yiannoulla's body.
The divorced father-of-two, who was still living in the local community, claimed he had a secret affair with Yiannoulla, even though the teenager was brought up in a traditional Greek Cypriot family and never had a boyfriend.
Her brothers and sister, who had sat through the distressing trial, broke down in tears as a jury at the Old Bailey took just over two hours to find Warnock guilty.
They said the loss of their beautiful sister had left the family "saturated by grief" although they never gave up hope.
Her brother Rick said: "Thankfully the long arm of the law has reached out from the past to bring this evil being to justice."
On August 13 1982, the victim, known as Lucy or Noodles, had been with her parents at their shoe repair shop minutes away from their Hampstead home.
Yiannoulla's mother, Elli, had sent her home to start preparing a leg of lamb for supper, saying she would join her soon.
She was playing the latest Patrice Rushen hit Forget Me Nots on the record player when Warnock knocked on her door at about 2pm.
Her parents arrived home half an hour later to "a sight beyond their worst imagining" - Yiannoulla's partially naked body lying on their bed, prosecutor Crispin Aylett QC said.
Despite a high-profile public appeal, including a televised reconstruction featuring her sister Maria, no real suspects were identified.
More than 1,000 people came forward with information but police were no closer to finding the doorstep stalker and the case remained unsolved for decades.
In efforts to keep the investigation going, her heartbroken father, George Yianni, appealed to then prime minister Margaret Thatcher and the commissioner of Scotland Yard. He never recovered from the grief and died in 1988 after contracting a brain tumour.
At the time of the murder, 5ft 6in Warnock was aged 22 and gave the impression of being a "cocky ladies' man", with his hair carefully salon-styled and blow-dried like his Saturday Night Fever idol.
But when officers tracked him down after matching his DNA to the crime scene, they found the heavily tattooed, balding and portly defendant awaiting their arrival, drinking beer in his underpants.
In a police interview he was asked what he looked like in the 1980s and he said: "How can I put it? Er, John Travolta?"
During the trial, Yiannoulla's brothers and sister relived the nightmare of her violent death while her now 86-year-old mother was among those to give evidence.
The dignified family were even forced to listen as Warnock, formerly of Harrington Street in Camden, north-west London, maintained his claim that he used to go to their home to have sex.
Following the verdict, Detective Inspector Julie Willats told how she was at the theatre last December when she received a text informing her of her "lucky break" in the case.
She said: "He must have known we would be coming for him. It's the science that has solved this one for us."
At the time of the murder, techniques in DNA testing had yet to be invented.
Warnock will be sentenced by Judge Nicholas Hilliard QC for the rape and murder as well as six counts of distributing indecent images in 2013 and 2015 to which he subsequently pleaded guilty.