Penned by BAFTA-winning writer Jeff Pope, the series dramatises the real-life story of Detective Superintendent Steve Fulcher, who went to great lengths to investigate the disappearance of a young woman, making decisions that ultimately cost him his career.

The ITV logline reads: “Sian O’Callaghan goes missing after a Friday night out in Swindon Old Town. As the family desperately waits for news, the police search for any clues as to where she could be.”

The series also introduces viewers to Karen Edwards, a mother whose daughter Becky also disappeared years earlier

Yes, the series is based on a true story. Set in Swindon, the drama centres around the disappearance of 22-year-old Sian O’Callaghan, who went missing after a night out with friends in March 2011. When she failed to return home, her boyfriend Kevin raised the alarm.

Detective Superintendent Steve Fulcher was assigned as the senior investigating officer on the case. Fulcher’s investigation led him to look into local taxi driver Christopher Halliwell, and in the hopes of finding Sian alive, he made the unusual decision to question Halliwell before taking him to the police station or giving him access to a solicitor – a decision that ultimately cost Fulcher his career and reputation.

Sherlock and The Responder star Martin Freeman leads the cast as DS Fulcher. He’s joined by This Country actor Charlie Cooper as Sian O’Callaghan’s boyfriend, Kevin Reape, Happy Valley‘s Siobhan Finneran as Sian’s mother, Elaine, Downton Abbey‘s Imelda Staunton as the other missing girl Becky’s mother, Karen Edwards, and Doc Martin actor Joe Absolom as suspect Christopher Halliwell.

Viewers have praised the series as an “incredible” drama and a “moving watch” on social media. One person wrote: “If you’re a fan of true crime and just good true stories that are also well acted, you shouldn’t miss this 6-episode show. Martin Freeman, Joe Absolom, and Imelda Staunton did an amazing job,” while another added: “Wow, one of the best dramas I’ve ever seen. Cannot believe it’s a true story. Harrowing.”

Meanwhile, a third person penned: “Just finished watching #AConfession @ITV. Wow @GoffPip, you have done it again. Incredible drama. Fantastic casting and acting. Emotional and so many questions in my mind. Well done, a brilliant moving watch,” while another binge-watched all six episodes, adding: “Wow, just binge watched the whole of #AConfession on @ITV. So intense, gripping and a shocking story. Amazing part played by Martin Freeman too!”