More than 170,000 people are reported missing in the UK each year but few yield a story as pitiless as the cover-up behind the disappearance of Tony Parsons. Murder Case: The Vanishing Cyclist (BBC2) was a tragic tale which was discomforting to watch because it exposed the level of callousness and cruelty of which seemingly “normal” people can be capable.

Parsons was trying to do something good, raising money for charity after surviving prostate cancer. Cycling alone 104 miles from Fort William to his home in Tillicoultry on a fundraising bike ride he was hit by a car driven byAlexander McKellar, who had been drinking in a bar with his twin brother, Robert. He suffered catastrophic injuries. We do not hear until near the end of this two-parter that he was still alive after the crash, possibly for 30 minutes, and that the two men heard him moan.

At this point it’s obvious what any decent human being would do — call 999. Instead they set about saving their own skin, driving off in the damaged vehicle and returning in another to collect the body and the bike then burying the lot in a shallow grave, thus condemning his family to a living hell.

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For the most part the film-makers told this tragic story well, despite limited crime visuals (only one CCTV image of Parsons on his bike was recovered) but with plenty of breathtaking Highlands scenery. It is also undeniable that documentaries featuring trials in Scotland are more immersive, with added drama simply because cameras are allowed in court and we see the culprits’ faces in real time. I can see the pros and cons of having cameras in courts but they certainly make for better crime documentaries, such as The Push on Channel 4 last year about the murder trial of Kashif Anwar, who pushed his pregnant wife off Arthur’s Seat in Edinburgh.

Here we saw in close-up the tears on the faces of the McKellar twins as they were sentenced, Alexander McKellar having eventually pleaded guilty to a lesser charge of culpable homicide and receiving 12 years in jail. But given what we learnt about him, those tears seem unlikely to be for the victim and his poor wife and children. Not just because of his sullen, repeated “no comment” when questioned but also from a recording on a phone in which he had allegedly said: “It was my life or his. The stupid f***ing c*** shouldn’t have f***ing been there.”

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But there was relatively little about Dr Caroline Muirhead, a girlfriend of Alexander McKellar, whose heroic actions helped to put the brothers behind bars. We heard a recording of her initial tip-off to the police after he confessed to her, three years on, taking her to the grave site on which, with great presence of mind, she dropped a can of Red Bull.

Muirhead, a forensic pathologist, also made recordings providing crucial evidence for the police but we learnt that she failed to attend the court trial. There was no mention of media reports from 2023 that she was planning legal action against the police after claiming that she came close to breakdown when police put pressure on her to stay with McKellar to keep watch on him. She claimed she had been threatened with prosecution if she failed to co-operate and had been “hung out to dry”. Two police officers reportedly resigned from the force before watchdogs could investigate complaints against them.

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I can see, given that, why she wouldn’t want to appear on camera but it felt odd not to mention that this had happened while focusing on the police success in what was otherwise a strong documentary. ★★★☆☆

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