I think this would make the criminals aware even if they were not to begin with!

PCSO Mark Wiley posts a warning to a motorist as part of the anti-crime drive

Police are using dummy parking tickets to shock careless motorists into keeping their valuables out of sight in their cars.

Officers are sticking fixed penalty tickets to the windscreens of parked vehicles which have laptop computers, mobile phones or satellite navigation systems on display.

But when the owners return to their cars they find the ticket holder contains nothing more painful than a crime prevention message.

City Centre Inspector Steve Baker, of Bradford South Police, said: "When people find the bright yellow Fixed Penalty Notice bag on their windscreen they automatically think they have got a parking ticket and take notice straight away.

"When they open it and read what it actually is, they are relieved not to have got a ticket but the crime prevention message makes more of an impact. It's not easy to quantify how successful it has been but we regularly have motorists telling us that it is a good idea and it has made them think more seriously about the security of their cars."

The recent introduction of the idea by Bradford South Police follows a vehicle crime reduction initiative which has been running in and around Bradford city centre for two years.

Patrolling officers note down the registration numbers of parked vehicles with property on display and send the details to the Driver Vehicle Licensing Authority, which sends the owners letters of advice.

The fixed penalty notices, bearing the West Yorkshire Police logo, inform drivers: "You have not committed any offence. The fixed penalty ticket pouch is to shock you into action."

The letter urges motorists to deter criminals by leaving nothing of value, like computers, wallets, cash and satellite navigation systems, on view and to leave the glove box open and empty. It adds that increased high visibility patrols and CCTV are monitoring the area.

The initiative is in use around the university area, where there has been an increase in vehicle crime, but may be expanded.

Insp Baker said: "More than 500 tickets have been given out in the last couple of weeks by police officers, Community Support Officers and Council street wardens. It is another tool in the fight against vehicle crime, and it works."