Christopher Halliwell: Martin Freemandrama now on Netflix

This means that several new eyes will be brought to the murder of two Swindon women at the hands of one of the town's worst criminals - Christopher Halliwell. 

A Confession, starring Martin Freeman and Siobhan Finneran, is a six-part series about the disappearance of 22-year-old Sian O’Callaghan, who was killed by Christopher Halliwell, 57, a private hire driver, after getting into his taxi when she left a Swindon nightclub in 2011.

Her body was found five days later in a shallow grave near the White Horse pub in Uffington, Oxfordshire.

Sian O'Callaghan (Image: PA) Former Sherlock star Martin Freeman plays the role of Detective Superintendent Steve Fulcher and the series follows the story of how he breached police guidelines to catch Halliwell, who was jailed for life for O’Callaghan’s murder and the 2003 murder of Swindon woman, Becky Godden.

Fulcher later resigned from his position after it was revealed he had interrogated Halliwell without a lawyer present and failed to caution him and despite being found guilty of gross misconduct, the mother of Becky Godden publicly supported him for achieving justice for her daughter.

After Halliwell was jailed for life in October 2012, police said there was a “distinct possibility” that he was a serial killer, particularly as there had been an eight-year gap between the murders.

Christopher Halliwell (Image: PA) Wiltshire Police continued to investigate Halliwell in the following years but 10 years on from O’Callaghan’s death, her mother Elaine Pickford has been left with unanswered questions.

She has since campaigned for Sian’s Law, which came into effect in 2022 and requires councils to carry out more checks on taxi and private hire drivers before issuing a licence and if they lose their licence due to sexual harassment, the information will be shared with all licensing authorities.

In 2021, Elaine told the PA news agency: “Ten years and people say time is a healer but the passing of time also brings home the time Sian hasn’t lived, how much she and us have missed out on, all the experiences she should have had and where she would now be in life.

“We as a family are coping and going forward, which I know is what Sian would want for us.”

A Confession is available now to stream on Netflix and the dramatization was written by Jeff Pope (See No Evil: The Moors Murders) and features former Eastenders star Joe Absolom as Halliwell, as well as Imelda Staunton and Peter Wight.