The number of accused and convicted U.S. offenders who are monitored with ankle bracelets and other electronic tracking devices rose nearly 140 percent over 10 years, says a survey by The Pew Charitable Trusts. More than 125,000 people were supervised with the devices in 2015, up from 53,000 in 2005. All 50 states, the District of Columbia, and the federal government use electronic devices to monitor the pretrial defendants or convicted offenders on probation or parole.
GPS technology accounted for the 10-year growth in electronic tracking, more than offsetting a decline in the use of radio-frequency devices. Despite the substantial growth of electronic tracking, it remains rare in the context of the entire corrections system, Pew said. Nearly 7 million people were in prison or jail or on probation or parole at the end of 2014, but people tracked using electronic devices in 2015 represented less than 2 percent of that total.