Murder Prevention (five); The Sand Marathon (BBC2): TELEVISION cops come in all shapes and sizes. We've have fat ones, thin ones, tee-total ones, drunk ones.

Many come with marital problems and troublesome children. One looks like an English spinster, while another of the Belgian variety who uses his little grey cells to solve crimes. Heaven help us, we've even met a singing detective.

Murder Prevention introduces a new kind of cop - one who arrests killers before they commit a crime. These detectives are not, however, psychic. They employ a combination of modern methods and gut instinct to work out who's likely to offend, watch and wait until they're about to step outside the law, and then arrest them.

This may all sound a bit far-fetched but apparently is based on a real-life unit at Scotland Yard.

Their methods and behaviour in the opening episode made you worry when their boss declared: "This is the future of policing." Preventing crime is commendable but not when they break the rules and trick witnesses as they do in the TV series.

One character said "we don't yet have a police state where people can be arrested before they commit a crime," but from the safety of the sofa it looked exactly like that.

The team assume someone is guilty before they commit a crime. If they don't have enough evidence, witnesses are bullied into making incriminating statements. You could argue that the ends justify the means, but it does seem very rough justice.

The real thing may be more acceptable. Murder Prevention is, after all, fictional drama which features the regulation bunch of misfits and mavericks we've come to expect to find in a cop series.

Two cases were interwoven in the first episode. One involved a woman being stalked by a man, whom the unit were convinced intended to attack and murder her on her daily run. The other concerned a young sex offender suspected of planning something with a former cellmate.

The style was fast and furious, grim and gritty with fancy camerawork and a relentless pace. Oh, and a lot of shouting too. This didn't give the actors much chance to register individually, although we can expect that the wide-eyed innocent look of the new profiler will soon be knocked off his face.

In the past, runners of The Sand Marathon - or Marathon des Sables to give the endurance race its proper name - have got lost or died. No matter, that didn't deter Ben Fogle from competing in the seven-day marathon across the Sahara Desert - described as 3.5 million square miles of rolling dunes, plateaux and barren scrubland baked by temperatures up to 49 degrees Celsius. This was clearly no walk in the park for the 600 competitors from 30 nations attempting the 240 kilometre (150 mile) race.

Race was, perhaps, not quite the right word for the latter stages when amateurs like Fogle were suffering with painful blisters on their blisters. "There's so much pain around here this morning," he said, hobbling to the starting post.

We were treated to the sights and sounds of the medical tent as the doctor "popped" blisters at the end of a tough day. The medic insisted on removing the entire blister, skin and all. I do hope you're not eating as you read this.

Published: 01/11/2004