It rather depends on what you think the police are for

We admit to sometimes being a little archaic around here. For example, in our attitudes to freedom and liberty. And so it is with our attitude towards policing: we are rather Peelite in what we think the entire game is about. We thus disagree with the police in this particular matter:

A gadget that alerts speeding drivers when emergency vehicles are nearby was last night facing calls by police and motoring organisations to be banned.

... a dashboard-mounted device which, astonishingly, is perfectly legal, according to its makers.

It can detect when police cars – even unmarked vehicles – are more than half a mile away by picking up encoded radio signals, and then sends a warning to the motorist.

When a 999 vehicle is within 1,200 yards, it sets off a green light on the display. As it gets nearer, the lights go to amber and finally they go red when it is just yards away. The device can even detect the radio signals from police officers on the beat and force helicopters.

... But last night Gwent Police Crime Commissioner Ian Johnston called for them to be banned.

He said: ‘This device is a passport to villainy and there is no legitimate reason for a law-abiding person to have one. The sellers are being very naive if they believe that they will be used to reduce accidents.

‘A criminal will carry out a drug deal, see a light on their dashboard and then ditch their illegal stash, only to pick it up when the police aren’t around – or a motorist will be speeding on the motorway, an alert will pop up and they’ll slow down.’

Devices that detect the position of speed cameras are legal for use on UK roads. Several years ago, legislation was proposed to make detectors with radar and laser illegal, but the ban did not go ahead.

If you think that the purpose of the police, of having a criminal justice system at all, is to punish the bad guys then you will be on the side of the police here. But if you are, like us and Sir Robert, of the belief that the having of those police, that justice system, is to reduce the number of bad things that happen then you will be entirely happy with this device. For, in that speeding example, it is not true that we wish to punish those who speed. We wish to reduce the amount of dangerous speeding that goes on, that's our primary goal. And if this comes about without having to punish anyone because people are not speeding then we are happier at that outcome than we would be if we had to expend resources to punish those who had sped.

It is exactly the Peelite argument: the police should reduce the amount of crime simply by their existence, by their presence. Punishment is only a back up to that idea. And here we have gadgetry which increases the amount of crime that does not happen for any particular police presence. It is a multiplier of the power of policing itself to achieve our goal. And who wouldn't want that?