Is 'Crimewatch' best clear-up squad in Britain?

Police hunting the killer of Jill Dando were investigating 20 new suspects yesterday, named by the public after a television appeal for witnesses.

The potential breakthrough, which includes details of two men who were named more than once, came after detectives issued new details on BBC's Crimewatch UK about a suspect seen several times near the murder scene.

The Dando inquiry and the huge public response to Wednesday night's appeal is the latest example of the police's willingness to turn to real-life programmes to help to solve the toughest cases. Some commentators are asking if programmes such as Crimewatch are becoming the most effective alternative police force.

In terms of crimes solved, public interest and pulling power among Britain's police forces, Crimewatch has an impressive record. With a national audience of between seven and eight million, detectives are falling over themselves to get their trickiest unsolved crimes on air.

But there is another side to the programme, with some police press officers complaining they are told that unless they come up with fresh information they have little chance of appearing.

Since the first episode in June 1984, Crimewatch boasts 582 arrests made as a direct result of the programme. Some of Britain's most notorious and apparently baffling crimes are among the successful results. Tip-offs telephoned in response to the programmes have helped police obtain convictions for the murder of Lin and Megan Russell, the multiple rapist Richard Baker, and Michael Sams, who kidnapped the estate agent Stephanie Slater. In the past few weeks important new information about the Stephen Lawrence murder has been obtained after a programme.

Photographs and surveillance footage of less sensational crimes, such as post office robberies and street muggings, have also led to instant results, with suspects identified in minutes of appearing on television.

Not surprisingly, detectives see Crimewatch and the plethora of copy-cat regional crime programmes as a cheap and effective tool. They also realise that criminals are far more likely to inform on fellow villains if they can ring a television programme rather than the police directly. But some officers are still suspicious about the television cops and only turn to an on-screen appeal as a last-ditch measure.

The makers of Crimewatch seem to have a perfect formula - high ratings and great publicity while carrying out a public service. Ian Hargreaves, professor of journalism at the University of Wales in Cardiff, believes the elements make a sure-fire hit. "People delight in a strange way in terrifying themselves about dark and evil goings on. When you combine that aspect of human nature with altruism, and give someone the chance to solve a crime you are pressing two of the most responsive buttons in the human psyche," he said.

He argued that the programmes contained a strong element of "public service television", but added: "There's some danger that as with all kinds of crime, reporting it makes the public think there's more [of it] and more evil crime than there really is."

Although the Crimewatch producers have to turn down many requests from police for appeals on the show, they also seek cases they think will make good television. This means a good sprinkling of murders and rapes alongside the more run-of-the-mill crimes.

And police press officers, while acknowledging the success and impact of the programme, complain that it does come at a price. "They do get results but sometimes they are rather in love with themselves - it's self-gratification," one senior press officer said. "They are also very, very tough about having to come up with a new angle for the case otherwise they can refuse to feature it."

Seetha Kumar, the executive producer of Crimewatch, said: "We are a useful investigative arm for the police and we have to have clear points to focus the appeal. Without that we let the public and the victims of crime down."

Meanwhile, Detective Chief Inspector Hamish Campbell, who is leading the Jill Dando inquiry, described 20 of the 200 new names telephoned in after Wednesday's programme as "relevant and interesting".