RUMMAGING through the cellar recently I stumbled across a dusty copy of Cluedo, the popular board game in which amateur sleuths tried to deduce who murdered the luckless Dr Black.

Was the killer unassuming, scholarly Professor Plum in the library with a revolver? Or Miss Scarlet, a blonde-haired femme fatale, who looks chillingly capable of wielding a dagger, in the dining room.

On a good (bad?) day, the game could last for hours. After this week, North Yorkshire detectives are unlikely to need so long investigating the slaying of The Burglar In The Bedroom With The Baseball Bat. Under new guidelines announced by the Government, householders were told they can attack and, if necessary, kill an intruder who is breaking into their home.

Homeowners can use weapons, such as knives, snooker cues or guns, and almost any level of violence to protect their family and property from burglars. Only where someone stepped over the line into revenge, retribution or trap-setting could they risk prosecution, said Director of Public Prosecutions Ken Macdonald (himself a burglary victim).

Tabloid newspaper editors rubbed their hands gleefully and tucked in. 'You can kill a burglar,' trumpeted the Mirror. 'You can kill a burglar,' boomed the Daily Mail. In a blinding flash of originality, the Daily Express shrieked... erm... 'You can kill burglars.'

Well, yes. But 'twas ever thus.

The law already allowed the use of "reasonable force" to defend one's home - an admirably vague legal term which meant it was practically impossible to prosecute someone who fought back in self-defence.

The law has not changed one iota. In only 11 cases in recent years have people been prosecuted for taking the law into their own hands against a house-breaker.

One involved a chap who lay in wait for a burglar, captured him, tied him up, knocked him about for a bit, tossed him in a pit and set him on fire. Pleas of self-defence fell on deaf ears. Another - and one reason ministers eventually reviewed the "reasonable force" law - involved Tony Martin, jailed for manslaughter after shooting dead a 16-year-old boy who was fleeing after being disturbed breaking into the farmer's ramshackle Norfolk home.

Contrary to what Tory leader Michael Howard - who says 99 per cent of people want tougher laws - believes, Britain's prisons are not overflowing with people jailed for tackling intruders. Most escape prosecution because the police accept they are acting in

self-defence.

Take the newsagent who stabbed a robber to death. Barristers prosecuted the surviving robber, who was jailed for six years. Or the householder who wrestled with a house-breaker who died after hitting his head on the driveway. Police said there was no case to answer - because he was defending his property. But one point the more inflammatory newspapers failed to raise was that you cannot kill a burglar just because you WANT to - only if you HAVE to.

Tony Blair's decision to publish leaflets clarifying the law does prove people were both concerned and baffled over how far they could go to defend their homes.

With the General Election expected in less than three months, and the Tories talking tough on crime, cynics may suggest the Prime Minister wanted to undermine their burglar-bashing rhetoric.

But whether Number 10 took a sensible course of action is debatable. If people get the impression that they can place a weapon under their pillow before going to bed, isn't it more likely that intruders will arm themselves before breaking through the window?

Studies in the USA, where homeowners are allowed to carry firearms to defend their "castle", show criminals are also more likely to carry guns. The fear in Britain must be that the guidelines will encourage householders and burglars to prepare for confrontation by "tooling up".

Homeowners will be emboldened to become "have-a-go heroes" - instead of ensuring their families are safe and dialling 999.

Offenders will carry weapons to "protect" themselves in case they face being clobbered by a person brandishing a candlestick.

This means detectives up and down the country will end up investigating fewer thefts of replaceable TVs, DVD players and stereos, and putting files together on more avoidable deaths.

Updated: 09:25 Friday, February 04, 2005