Keeping offenders out of prison should cut costs

From April, a Global Positioning System (GPS) pilot scheme will track criminals rather than imprison them.

GPS tracks all movements, unlike electronic tagging - already used in the UK - which sets off an alert when perimeters have been broken.

GPS is already used to track offenders in the US, and British officials hope it will help cut prison overcrowding.

Florida scheme

It could also halve the cost of keeping an offender in prison.

Home Office officials have visited a US Department of Corrections centre in the state of Florida, which monitors 3,000 convicts tracked by the satellite system.

Offenders are linked to the GPS system, which they carry with them, by an electronic anklet.

Their movements can be tracked on screen to ensure they are not, for example, going into a restricted area such as a school or banned street.

If offenders are on a curfew, their movements can be tracked to check they are where they are meant to be at the time.

Florida spokesman Joseph Epapy said : "The community would always prefer that all criminals be in prison... when they realise the price tag that comes with keeping everybody in prison they realise that some are going to have to be supervised in the community."

A smaller and lighter version of the monitoring device is now being developed for use in Britain.