The Investigator: A British Crime Story is too slick - but you'll be hooked by the disappearance of Carole Packman

What emerges over the four-part series is a strange, unnerving tale of deception, infidelity, greed - and more deception. Williams-Thomas interviews people who knew the convicted murderer Russell Causley, and those who investigated Carole's disappearance at the time. He also spends a lot of time talking to her daughter Sam, who now has her own grown-up son.

Tortured by the fact that she doesn't know what happened to her mother, Sam sees this investigation as her final chance to get some peace of mind. So palpable is her pain, her to-camera interviews are sometimes quite hard to watch as she struggles to hold it together. And it's no wonder she's so distraught. Russell was clearly a controlling, aggressive father who, in keeping silent about his crime all these years, still holds an unbearable power over her.

Unlike Piers Morgan's sensationalist interviewing in ITV's lurid Killer Women, Williams-Thomas's investigation is sensitive and balanced. You don't feel he's trying to massage the story to make it seem more intriguing than it really is, and the fact that he was involved in the unmasking of Jimmy Savile gives the doc some extra clout.

However, perhaps because it's made by Simon Cowell-owned Syco Entertainment, it's sometimes distractingly slick, looking and feeling like an episode of The Apprentice or Dragons' Den, with gleaming glass offices, dimmed lighting and a heightened sense of drama. We are told at the start that this is a tale of "twists at every turn... murder... sex... and fraud", which sounds like a description of a salacious drama rather than a deeply sad murder case.

https://www.youtube.com/watch?v=BIp90BrXWZw

But none of this ruins a series that leaves you wanting more at the end of each episode. It's been billed as Simon Cowell's version of Making a Murderer and while it's definitely not as hauntingly brilliant or well done as the US Netflix hit, it'll give British audiences plenty to speculate and obsess about. Like Making a Murderer, or the record-breakingly popular podcast Serial, A British Crime Story makes you doubt the conclusions you come to each week - and therein lies the enjoyment. You think you know what happened and then BAM, you're suddenly back to square one.

What also keeps you hooked is that you're fully invested in Carole's daughter Sam. You're rooting for her to get some answers from Williams-Thomas, because she seriously needs them after living most of her life wondering whether her father is truly a killer. If so, why and how did he do it? And alive or dead, where on earth is Carole Packman?