Law & Order: UK ITV1

"IN the criminal justice system," a very serious voice tells us at the start of Law & Order: UK, "the people are represented by two separate yet equally important groups – the police, who investigate crime, and the crown prosecutors, who prosecute the offenders."

Where Hetty Wainthropp fits into all this, I don't know.

"These are their stories," says the serious voice, a statement which would have with slightly more gravitas were the series not to star Bradley Walsh, an actor only slightly more convincing as a policeman than Balamory's PC Plum.

I always expect his investigations to be put on hold while he nips off to present a daytime quiz on Channel Four.

This week's instalment told the cheery story of a teenager who'd collapsed on a railway concourse.

Initially, it was assumed to be just another case of sausage roll poisoning, but the post mortem revealed she'd got 70 condoms filled with heroin in her stomach.

The case confused Walsh. Debbie was a nice middle-class girl, the sort who acquire their moral compass from a fortnightly edition of the Bunty.

With a university course beckoning – tanning salon management at the University of Central Doncaster – what was she doing risking all for life as a drugs mule? It just goes to prove what I've said for a long time – girls of an impressionable age should be sat down and made to watch a particularly harrowing edition of Prisoner Cell Block H. That one where Bea Smith traps a warder's head in the industrial steam iron.

I'm not saying the culprit in this mystery was telegraphed from the start, but the only way it could have been more obvious was if he was wearing a loose-fitting outfit with arrows up the side.

A family friend of a dodgy disposition, not an MP, had embarked on an affair with the victim, using her infatuation for his own unpleasant means. But he was as slippery as an eel in a lard factory and somehow he managed to persuade a jury of his innocence.

Thing is, the law enforcement agencies of this country don't just give up on his sort.

If they fail on one flank, they launch an attack on another. There's always something they can get them for – littering with intent, driving with an offensive haircut, taking a fag-break without consent, that kind of thing.

And thus it was that they tore into this swine's tax returns with a fervour not seen since the arrest of Ken Dodd, revealing a fraud of some £400,000.

He only got two years, but, said one of his prosecutors, "life as he knows it will never be the same again."

No, by the time he comes out Bradley Walsh will be hosting Deal Or No Deal.