Using GPS to Monitor Sex Offenders
GPS monitoring uses satellites to calculate an offender's physical position. The offender wears a tamper-resistant bracelet
— typically worn around the ankle — that receives transmissions from the satellites and calculates the offender's location.
In "passive" monitoring systems, this information is stored and transmitted at appointed times to a monitoring station. In
"active" systems, information on the individual's location transmits to a monitoring station in near real time, allowing the
station to alert officers immediately when a violation occurs. Both systems allow exclusion zones (such as schools or other
places where children congregate) or inclusion zones (such as a workplace) and provide information on when and where an individual
has been throughout the day.
In California, sex offenders designated as high-risk are placed on actively GPS-monitored caseloads, while non-high-risk sex
offenders are on passively GPS-monitored caseloads. However, in the state, information in both caseload types is received
at near-real-time intervals. The difference is that information in the active system is reviewed more frequently than information
in the passive system. Vendor-operated monitoring centers track this information and email daily reports to parole agents that
detail all of the activity recorded by the GPS device. The centers also send an immediate alert notification to agents via
text message whenever the GPS device records an inclusion/exclusion zone violation, tampering with the strap, a low battery,
a cell communication gap or no GPS communication.
Date Created: February 27, 2013