Only this spring there were those who doubted the level of Serbian atrocities in Kosovo. John Sweeney's Dispatches for Channel 4 in April set out to answer the doubters by going to Albania and finding refugees from a village called Little Krusha who told in heart-stopping detail of the massacre of 100 men, shot and burnt in a hay barn. Witness to Murder has since been nominated for an American Emmy. This week's follow up, Prime Suspects (Thursday, Channel 4), seemed to me even more impressive.

As they filmed over the summer, Sweeney and his producer-director Gerry Greg must have known that by transmission date their difficulty would not be in convincing us that the massacre took place but in making us care about it now that the Butcher of Belgrade was safely back in his lair and the story had its happy ending. Their response was to continue the Little Krusha narrative half as a whodunnit, and half as a personal crusade. This Dispatches was, Sweeney announced, "a manhunt" and "a detective story but not by Agatha Christie". He was in pursuit of "Milosevic's Willing Executioners".

When he arrived, there appeared to be no one in Little Krusha. Then, like the boy in Life Is Beautiful, a young survivor emerged from nowhere and gave Sweeney a tour of his parents' gutted bedroom. "I couldn't bear," said Sweeney in low voice-over, "to tell him he'd never see his father again. The hunt for his killers was no longer just a job." Sweeney was back, and this time it was personal.

You can either take this reporter's self-dramatising or you cannot. Exploring the home of one of the departed Serbian suspects, he told us he had to be careful since there were "booby traps all over the place". When he discovered the killers were now in Serbia, he did not refrain from telling us how long ago he had heroically been banned from the country. His scripts have a tabloid bombast about them - "Here the damned chose the doomed," he intoned on the site of the hay barn - but they are always vivid. It was easy to identify the Serb homes, he said: they were the ones with roofs still on. For myself, I like idiosyncratic journalism (I may well be the only person in the country not to find the BBC's advert for its own team of cranky foreign correspondents risible). As for Sweeney, who is one of my oldest friends in journalism, let me say if his rhetoric looked high-flown in Kosovo, you should have seen it soar over South Yorkshire, where its author won his wings on the Sheffield Morning Telegraph 20 years ago.

What there can be no doubt about is the effectiveness of the way he personalised his subjects on this occasion. When the refugees returned to the village, the cameras did not flinch from the wailing grief of the women nor as they identified their dead through the charred remains of their fly-zips. Just as Witness to Murder had brought the massacre's victims back to life through their home videos, a stash of their videos this time spun the prime suspects back to the riotous days of parties, farmyard impressions and, surreally, cross- dressing. A reel showed a young Serb affectionately kissing his bride on the porch of his home as he headed off to war in 1991. This willing executioner, we were told, died by one of the last Nato bombs of the war. If Sweeney had meant to demonise his quarry, he ended up doing something more interesting. He humanised it.

Next to Kosovo's civil war, Enoch Powell's confident prediction of a British race war looked particularly wicked when it was replayed on the second part of Playing the Race Card (7.10pm, Sundays, BBC2). This fascinating examination of how our politicians reacted with courage, timidity but mostly pragmatism to mass Commonwealth immigration has produced some unlikely heroes. Virginia and Peter Bottomley took in a Ugandan Asian family, for example. Their fellow Tory, John Wheeler, chairman of the Commons home affairs committee, was praised by a black south London mother for his support for her campaign to scrap the sus laws. Shirley Williams called Robert Carr a "remarkable" home secretary for standing up to the Conservative conference at the time of the Ugandan expulsions: "We put a great deal into our Empire and we took a lot out," he told it. "We have our imperial heritage and obligations and to those we will stick."

There, on the Labour side, Roy Jenkins scratched his chin with the effort of remembering why his 1976 Race Relations Act had exempted the police force from its terms. It was not too much of a surprise to discover he had fallen out with his immigration minister, the late Alex Lyon, who would stay up late overturning his officials' advice and allowing families into Britain. The co-builder of this Schindler's Ark was Lyon's civil servant, Clare Short. It was love over the red boxes, and they married. Playing the Race Card is observant on policy but, as with the Sweeney film, it is its eye for human detail that hypnotises.

Andrew Billen is a staff writer on the London "Evening Standard"