Here is a timeline of events in the long-running case.
– January 3: Sex worker Becky Godden, 20, is last seen in the early hours getting into a taxi outside Desire and Destiny nightclub in Swindon.
-Miss Godden is reported missing by members of her family.
– March 18: Office worker Sian O’Callaghan, 22, goes for a night out with friends in Swindon. She fails to return home and is reported missing the following day by her family.
– March 21: Detective Superintendent Steve Fulcher, leading the investigation, says he has been trying to establish Miss O’Callaghan’s movements.
– March 22: Christopher Halliwell becomes a “Tie” – a person to Trace, Interview and Eliminate after his car is seen in the area where Miss O’Callaghan disappeared.
– March 24: Halliwell is arrested. An “urgent interview” is carried out by detectives. Halliwell starts journey to Gable Cross police station but is diverted to Barbury Castle where he meets Mr Fulcher.
Halliwell shows detectives the location where he hid Miss O’Callaghan’s body and later directs them to Eastleach, Gloucestershire, where years earlier he had buried Miss Godden.
– March 26: Officers announce they have found human remains following extensive searches at Eastleach. Mr Fulcher says he had been told they were those of a woman abducted in Swindon between 2003 and 2005.
– March 26: Halliwell is charged with the murder of Miss O’Callaghan.
– April 4: The police knock on the front door of Miss Godden’s mother Karen Edwards and tell her they have found the body of her daughter. It would have been Miss Godden’s 29th birthday.
– May 23: Halliwell is charged with the murder of Miss Godden.
– June 4: Mr Fulcher steps down as senior investigating officer (SIO) in the case, and is later investigated for misconduct over the way Halliwell’s confession was obtained.
The case is without an SIO for more than a year.
– January 30: A week-long abuse of process hearing begins at Bristol Crown Court. Barristers argue Halliwell cannot get a fair trial because of breaches of the Police and Criminal Evidence Act (Pace) codes and briefings given to the media by Mr Fulcher.
The trial judge, Mrs Justice Cox, rules Halliwell’s confessions to the murders of both women are inadmissible because of breaches of Pace.
– October 19: Halliwell pleads guilty to the murder of Miss O’Callaghan during a hearing at Bristol Crown Court. He is jailed for life and told he will serve a minimum of 25 years by Mrs Justice Cox.
– February 18: Halliwell is arrested on suspicion of the murder of Miss Godden. He tells Superintendent Sean Memory he will accept responsibility for Miss Godden’s murder provided the police do not ask further questions about other offences he may have committed.
– March 30: Halliwell is charged with Miss Godden’s murder.
– September 5: Halliwell goes on trial at Bristol Crown Court for Miss Godden’s murder.
– September 19: Halliwell is convicted of Miss Godden’s murder.
– September 23: Halliwell is sentenced to a whole life order by the judge, and will never be released.
– September 2: The Independent Office for Police Complaints publishes a report finding there was ample evidence to prosecute Halliwell in 2011 for the murder of Miss Godden.
It finds Wiltshire Police did not follow up leads for many years in some cases.
Wiltshire Police issues a formal apology to Miss Godden’s family.