The six-part series follows the disappearance of Swindon office administrator Sian O’Callaghan. The 22-year-old was murdered by cab driver Christopher Halliwell, since also convicted of the murder of Becky Godden-Edwards.

READ MORE: ITV's A Confession Episode One focuses on early stages of investigation into Swindon girl's disappearance

READ MORE: Timeline of investigation into double killer Christopher Halliwell

Directors cast Hobbit actor Martin Freeman as Det Supt Steve Fulcher, the detective initially charged with leading the investigation. Imelda Staunton took the role of Karen Edwards, Becky’s mum, and Elaine Pickford – Sian’s mother – was played by Siobhan Finneran.

Picture: ITV

While the action was set in Swindon and Savernake Forest, much of the drama was shot elsewhere.

Commenting on the Adver’s Facebook page last night, Helen Andrews said the search for Sian felt like only yesterday: “Feeling for Sian and Becky’s families and friends tonight.”

That sentiment was echoed by Ali Shuttleworth Jones, who said: “A tough watch for all those who knew her so well.”

Others commented on the stage direction.

Nikkita Hicks said the actors sounded more Bristolian and Swindonian: “Accents were terrible.” Roisin Stratford said she had been baffled by the West Country accents.

Simon Tilbury questioned the camera work. Quick zoom effects left some viewers feeling a little sea sick.

However, Tracy Bridgman wrote: “This is not about accents. It’s about two young ladies who lost their life to a sicko and a copper who did what he thought was right to bring the b****** to justice.”

A Confession continues next Monday, 9pm, on ITV1.