What happened to Sian O’Callaghan, when was she murdered and who is her killer Christopher Halliwell?
SIAN O'Callaghan was just 22 when she was abducted and murdered after a night out in Swindon. Her killer later took police to her body.
Here's what we know about Sian and the sicko who stabbed her to death.
Who was Sian O'Callaghan?
Personal assistant Sian O’Callaghan, 22, was abducted by Christopher Halliwell as she made her way home from a night out in Swindon.
Halliwell was arrested five days later after CCTV showed Sian getting in his green Toyota Avensis taxi outside a nightclub.
He confessed to killing her and took police to her body.
He was jailed for life for her murder.
Sian's mum Eliane Pickford has revealed she "always thought" her daughter's killer was involved in more murders.
The ITV series A Confession is a true crime series based on Sian's murder.
When was she murdered?
Sian was on her way back from a nightclub in Swindon when she was abducted by her killer Christopher Halliwell in the early hours of March 19, 2011.
Her partially naked body was found near Uffington, Oxfordshire.
Who is her killer?
Taxi driver and former burglar Christopher Halliwell, 52, lived with his partner Heather Widdowson and her three daughters in a suburban semi in Swindon.
Brian Jerome who lived nearby said at the time of his arrest: "He's a really nice guy. He'd always have a smile and he'd often be out working on his car.
"I couldn't believe it when I heard. Nice man, nice family, nice girls."
Halliwell is a father of three children himself with ex-wife Lisa.
Fellow minicab driver Neil Barnett said: "Real nice bloke, a genuine bloke, a normal run-of-the-mill bloke. I've got two daughters I would have trusted them in his car."
But the respectable family man had a sinister side and was regularly using prostitutes.
Hookers who were picked up by Halliwell in the weeks before Sian’s death said he got "rough and weird" with them, and some got frightened and called for help.
Police say he had a brutal childhood and has "issues" with women.
Detectives fear he may have killed many more victims after he boasted he wanted to be a serial killer like his idol Myra Hindley.
Halliwell has been linked to a string of women who went missing in his home town.
The cop who nailed him for killing Sian has also linked Halliwell to the disappearance of Claudia Lawrence in York - where his father lived close by - in 2009.
LATEST CRIME NEWS
Is ITV's A Confession accurate?
Following on the success of Manhunt, A Confession is another crime drama which deals with a real-life case.
It tells the story of 22-year-old Sian O’Callaghan who went missing in Swindon in 2011 after leaving a nightclub to walk to her boyfriend's house.
Senior Investigating Officer Steve Fulcher is in charge of handling the case and firmly believes that Sian is still alive.
In the end he links Sian's case to the disappearance of Becky Godden-Edwards and breaches police procedure to ensure that justice prevails.
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