Though commercial applications are driving the use of radio frequency identification (RFID) tags, the technology is developing a niche in U.S. correctional facilities. 

RFID can be used as a tracking system in prisons, which lets correctional officers keep tabs on inmates and mitigate or prevent disturbances.

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."

RFID technology is strictly for security, and won't eliminate 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."

RFID tracking systems differ in price depending on the facility's size that's being outfitted. The Lino Lakes deployment is expected to cost about $500,000. "You have to buy a system," said Greg Oester, president of Alanco/TSI Prism, an Alanco Technologies subsidiary that supplies RFID systems.

"Basically you have a contained RFID system, meaning we place antenna around and throughout the prison facility that allows us to capture signals that come off the tamper-detecting bracelets that inmates and staff wear," Oester said. "The staff will wear a pagerlike device under their belts and inmates will wear a tamper-detecting bracelet on their wrist."

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," Oester 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."

In the event of an assault or other emergency situation, staff will immediately know the identities and prison histories of everyone involved because every infraction committed by an inmate is stored in a database.

Investigations can be finished much more quickly, and the facility can avoid going into lockdown mode, which puts a strain on staff.

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.

The systems also can track an inmate suspected of being a "mule," or a contraband carrier. The person can be tracked all day to see where he goes and with whom he is in contact.

In its limited use thus far, RFID has proved its worth as a security tool for correctional systems. As prisons continue to deal with overcrowding, RFID could be a necessary piece of equipment in the future for corrections.

Jim McKay, Justice and Public Safety Editor  |  Justice and Public Safety Editor