Movements of sex offenders may by tracked by GPS tags
Sex offenders could be tracked by GPS devices fitted inside their tags if government proposals get the go-ahead.
Ministers have launched a consultation on the use of the satellite tracking technology to monitor and control the movements of offenders.
It could set up "exclusion zones" alerting the authorities if an offender was near a school or playground.
Courts have had the option to impose electronic monitoring of offenders for a number of years.
They are typically used to control the movements of prisoners released into the community early from their sentence.
Sheriffs can impose a curfew during which the offender must remain at home.
One high-profile prisoner to wear a tag was former MSP Tommy Sheridan who was released from prison after serving half of a three-year sentence for perjury.
He was tagged for the remaining 18 months of his jail term.
But the government wants to go further, using GPS technology to track where offenders are.
Since April, a new electronic monitoring contract has been in place which would allow for GPS capability to be included in a tag.
The government consultation seeks views on how the technology could be used - and which types of offenders should be affected.
Justice Secretary Kenny MacAskill said it would help allay public concern about prisoners released into the community - particularly those convicted of sexual offences.
"Scotland's monitoring of these offenders is already among the most stringent anywhere," he said.
"I want to see if there is more we can do to help further improve monitoring of offenders and give greater re-assurance to the public."
Apart from sex offenders, other groups who could be followed by GPS tags include those on bail awaiting sentence.
The technology could also be used to identify easily if a suspect wearing a tag had been in the area of a new crime or quickly eliminated from inquiries,
This idea of using GPS was first put forward in 2000 in Lord MacLean's report on the treatment of serious violent and sexual offenders.
The High Court judge visited the Sexually Violent Predator Programme in Phoenix, Arizona, where offenders were under constant satellite surveillance, their movements constantly monitored in a control room.
There were technical problems with the system as signals could be disrupted by tall buildings or trees. These have now been overcome.
The government is also seeking views on the use of "alcohol bracelets" to take readings from an offender's skin, to monitor remotely how much they have been drinking.