Carroll County authorities are using GPS to monitor a man convicted of a crime to "verify that he's not harassing a witness," said Deputy 1st Class Doug Welty of the Carroll County Detention Center
For Harper, the GPS device might be his final opportunity to avoid spending more time in prison. Twice convicted of cocaine possession, he watched his younger brother die in a gunfight over drugs, and then he fatally shot the man he thought had pulled the trigger. He served two years in prison for manslaughter.
Harper pleaded guilty this month to selling cocaine. Baltimore Circuit Judge John C. Themelis agreed to put him on home detention and GPS monitoring. In an interview, Themelis said that one misstep could result in Harper being sent back to prison for up to eight years, minus any time he successfully spent in the program.
"This is the first time I'd ever heard of GPS," Themelis said. "But it was described to me as a system whereby they could confirm the whereabouts of a person on home detention at any time. He was employed. He was supporting a family. And the state didn't object."
Standard electronic monitoring of people on home detention is far less sophisticated than GPS tracking. Under the traditional radio-frequency method, correctional officers can only know when offenders are home - and thus, whether they've missed curfew.
"I was trying a case where the person was on standard home detention and accused of running out of the house, around the corner, shooting someone in the head and running back," Themelis said. "His defense was that he was on home detention, and a brief breach of the zone - oftentimes it's considered a [glitch] in the system and not reported. The long and short of it was that the home-monitoring agency couldn't really tell me whether it was a bleep, or whether or not the defendant ran out of the house, around the corner and back."
The most advanced GPS systems, called "active systems," can pinpoint someone's whereabouts in real time with about 100-foot accuracy. Depending on the capabilities of the system, as well as the requested intensity of the monitoring, an offender's GPS trail is automatically uploaded to a secure Web site every minute to every four to six hours.
For the system to be useful, however, that Web site has to be regularly checked.
"We still do our homework," said Arthur Wallenstein, director of the Montgomery County Corrections Department of Correction and Rehabilitation. "Slapping somebody with a GPS unit does not create public safety. It's merely a tool."
