Though commercial applications are driving the use of radio frequency identification (RFID) tags, the technology is developing a niche in U.S. correctional facilities.
Correctional facilities in California, Virginia, Michigan, Illinois, Ohio and Minnesota have deployed RFID tracking systems to help manage inmates. This spring, the Minnesota Department of Corrections is deploying an RFID tracking system in its 1,300-inmate, minimum- and medium-security facility in Lino Lakes that houses sex offenders. The 87 minimum-security Lino Lakes inmates will be fitted with an RFID device to ensure they don’t escape. Because they have no secure fence around their living area – because it’s minimum security – they have the opportunity to leave illegally if they choose to, and we want to prevent that from happening,” said David Crist, a Minnesota Department of Corrections assistant commissioner. “The offenders wear either an ankle bracelet or a wristband, and if they go outside that radio frequency perimeter, it sends a signal back to a computer at a security station telling us someone has left the radio frequency perimeter.”
The system helps security but doesn’t save on personnel.
“We’re not reducing any staff and we’re not making any other operational changes,” Crist added. “In fact, as an operating system goes, it adds expense because we have to buy new wrist and ankle bands, replace batteries, and at some point we’ll have to upgrade the computer software”… The Lino Lakes deployment is expected to cost about $500,000.
Tracking is the key to the system.
Each transmitter constantly sends off a unique signal that’s captured by the antenna and then processed through the computer system, which determines where the subject is at each two-second interval. “That allows us to know where everybody is at any given time,” Greg Oester, president of Alanco/TSI Prism, an Alanco Technologies subsidiary that supplies RFID systems, said. “So if I’m looking for someone, I don’t have to go out in the facility and hope I can find them among 500 or 2,000 inmates, or whatever it is.” The system also makes investigating an incident easier because the system shows exactly who is involved – and where. “That shortens the investigative process because you don’t need to rely on reluctant or intimidated witnesses,” Oester said. “Say there was a guard or inmate assaulted. I know who was there, and the investigative team can focus on the guys who were around when the officer was assaulted.”
… Prison administrators can use RFID tags for other purposes, such as keeping rival gang members away from one another. The system can be set up to trigger an alarm whenever rival gang members get within 10 feet of each other.
Government Technology gives a lot more details.
vericatrajkova California, Electronic Monitoring, Illinois, Michigan, Minnesota, Ohio, RFID, Virginia
A comprehensive plan to enhance security inside jail premises across West Bengal has been approved by Chief Minister Buddhadeb Bhattacharjee, as reported by Express India. 
The Borneo Bulletin reports