State officials wrestling with efforts to reduce California's prison population - both because of budget cuts and federal court orders - are considering increased use of GPS monitoring to help keep some inmates from being returned to prison. But there already are 7,921 parolees statewide being monitored by GPS, almost all of them sex offenders.

The totals range from one parolee in Mono County to 1,722 in Los Angeles County. Sacramento County monitors 465, El Dorado has 38, Sutter has 14, Yolo County has 72 and Yuba has 70.

Those most closely monitored are high-risk sex offenders on "active" GPS, meaning their movements are tracked in almost real time. Other sex offenders are on "passive" monitoring, meaning the tracking unit sends its location at set intervals throughout the day. A small number of gang members also are monitored through "passive" GPS.