Last Night's Television: Real Crime, ITV1,<br> Who Do YouThink You Are? BBC1

On Sunday evening, Mrs Viner and I stayed up well beyond our usual bedtime to watch Atonement, the handsome-looking adaptation of Ian McEwan's excellent novel about a miscarriage of justice. But last night came a timely reminder that in the real world miscarriages of justice do not look handsome, and do not feature Keira Knightley taking her clothes off. Real Crime examined the tragic case of Lesley Molseed, the 11-year-old from Rochdale abducted in October 1975 while on an errand to buy a loaf of bread, and whose savagely stabbed body was found on moorland three days later.

The murder was a tragedy on several levels: for Lesley and her distraught family; and for the heartbroken mother of Stefan Kiszko, the huge man-child forced by police into making a confession, then wrongly imprisoned for 16 years; and of course for Kiszko, who was relentlessly persecuted by his fellow inmates and died of a heart-attack just 18 months after stating, following his exoneration, that his ambitions were "to get married, go on holiday, and enjoy my life as much as I can"; but also for the son and former wife of the man who really did it, Ronald Castree. They talked candidly and movingly about the effect on them of discovering that Castree was not just abusive, prone to violent mood swings and "totally weird in the bedroom department", but also a paedophile and a child-killer, and Beverley, the ex-wife, broke down when she recalled the magnanimity outside the court of Lesley's family, who, satisfied that she had known nothing of Castree's repugnant crimes, told her to "go out there and hold your head up". For heartrending poignancy, no amount of tearful pouting from lovely Keira the night before had come close.

On only one score was there a parallel between Atonement and Real Crime, and that was the score. I am waging a losing campaign in this column against the superfluous use of music on television, but it won't stop me waving the placards. Real Crime told a harrowing story with admirable economy and restraint, except when it came to the percussion and strings. Why add music to a documentary like this? To make it more suspenseful? To ratchet up the emotion? Or just because everyone else does it? Whatever, it's an insult both to the subject and the audience.

That apart, the producer-director, Tom Gould, did a fine job. As far as possible he let the people closest to the tragedy tell the story, and was rewarded with simple eloquence. "Lel, bless her cotton socks, had been murdered again" was the verdict of one of Lesley's sisters when a crucial piece of forensic evidence, overlooked in the original trial because it incoveniently proved that Kiszko could not possibly have been the killer, secured the poor fellow's release. Happily, insofar as such a story can end happily, in October 2005, Castree was arrested on suspicion of raping a prostitute and a DNA swab taken, which yielded a perfect match with fibres removed from Lesley's clothes. The police had their man, albeit 30 years late.

In Who Do You Think You Are?, genetic science featured again. "There's salt in my DNA," said Laurence Llewellyn-Bowen, proudly. The flamboyant interior designer had established that several of his forbears were sailors, and made the obvious connection with his fabulous second home in Cornwall. No matter that he prefers waves in his hair to waves under his feet, he feels the lure of chic Port Isaac – and no wonder, with his late grandfather having been on a merchant ship sunk by a German submarine, in the dangerous waters between Sicily and North Africa, in 1917.

This series is precisely as good as its subjects, and the programmes on Jerry Springer (whose two grandmothers died in Nazi concentration camps) and Patsy Kensit (whose father was a gangster) were very good indeed. Llewellyn-Bowen's family history was consierably less enthralling, which is no doubt why such pains were taken to establish exactly what happened when the Kohistan was sunk, by U-boat UC35, in the Med. Apparently, 6,500 merchant ships were sunk by the Germans during the First World War, killing 2,000 British sailors, but mercifully for the future development of home-makeover programmes, Llewellyn-Bowen's grandfather survived, along with everyone else aboard the Kohistan that day. I'm delighted they did, of course, though Llewellyn-Bowen's conclusion that "it must have been a really scary experience" perhaps fell just short of justifying the time and effort expended on the research.

Still, I enjoyed the detail that the Royal Navy, in the form of HMS Narcissus, had flunked the job of keeping the Kohistan safe. Not because the captain, a Commander Dunlop, was drunk at the time, although he allegedly was, but because the name Narcissus should pop up in the background of a man who, in the course of my occasional work as an interviewer of TV celebrities, is by some distance the most narcissistic I have ever met.