The Martin Freeman drama is based on two real-life murders.

Avid crime-drama telly-lovers will likely be well aware by now that a huge proportion of chilling shows are based on harrowing true tales.

Within the last week alone, Netflix viewers have been left shook after discovering that spine-tingling eight-part limited series Unbelievable is based on the real life experience of Denise Hutchins, who was kidnapped, released and branded a liar by police back in 2015.

And this week, thousands of ITVX viewers have stumbled across a 2019 British police drama after it’s recent release to the catch-up hub, and were seemingly unaware that the show is based on a murder case that horrified the UK back in 2011.

Starring the likes of The Hobbit star Martin Freeman, The Crown’s Imelda Staunton and Happy Valley’s Siobhan Finneran, A Confession tells the tale of the sudden disappearance of a young woman following a night out with friends.

In the show, Freeman takes on the role of Detective Superintendent Fulcher – who fronted the former investigation – and confronts a suspect that leads him torn as to whether to ‘break protocol’ in order to catch the ‘psychotic killer’.

And viewers are hooked by the series, with one person writing on social media this week: “Martin Freeman never disappoint[s] me and he proves me it again in ‘A Confession’.”

Another went on to give the show ’10/10′, while someone else called it ‘gripping’.

Perhaps unbeknownst to some viewers, A Confession is based on a harrowing true story of two women that were murdered eight years apart by the same man.

In 2003, 21-year-old Becky Godden-Edwards was brutally murdered and dumped in a nearby her home in Wiltshire.

It wasn’t until 2011, however, that Becky’s killer would be brought to justice.

That year, after getting into a taxi following a night out clubbing with friends, 22-year-old Sian O’Callahan was reported missing by her boyfriend.

Police subsequently made an urgent appeal for witnesses of a green Toyota with taxi markings, and days later, cab driver Christopher Halliwell was arrested the same day Sian’s body was discovered by police in a shallow grave.

Despite admitting to both crimes whilst in custody, however, the lead investigator DS Steven Fulcher failed to caution Halliwell and denied him access to a solicitor, meaning his statements were inadmissible in court.

Instead, the detective controversially acted on a window of opportunity, where after Halliwell admitted to Sian’s killing, he should have taken the killer back to the police station, DS Fulcher instead drove him to the field on the assurance that he’d be lead to another body.

In October 2012, Halliwell was sentenced to life for the murder of Sian, but not Becky, leaving her family devastated.

Due to the mishandling, DS Fulcher resigned in 2014 – but Becky’s mother Karen (played by Staunton in the series) commended him at the time: “Had he have followed the guidelines, then Becky would never have been found, she would have never have come into the equation.”

In 2016, Halliwell was finally charged with Becky’s murder after new evidence surfaced and he was sentenced to life imprisonment with a whole life order for the murder, meaning he would serve his sentence without the possibility of parole.

Wiltshire Police

Three years later, ITV produced A Confession, telling the true story of the police’s and family’s hope to bring a double-murderer to justice, as well as the inadvertent harm they caused to the case by doing so.

And in 2022, an investigation by the Independent Office for Police Conduct found that Wiltshire Police had missed significant opportunities to bring Halliwell to justice sooner and ten recommendations were made on managing investigations.

IOPC regional director Catrin Evans said: “In our view, the issues that arose stemmed from a combination of systemic weaknesses within the force at the time as well as individual shortcomings.

“Our investigation indicated that no one in Wiltshire Police took responsibility for ensuring that the murder inquiry progressed effectively.”

They added that Wiltshire Police had ‘have already acted on a series of recommendations to try to ensure that mistakes the force made over the accountability for, and direction of, this murder investigation are not repeated’.