The decision by Judge Allen Baddour was the latest setback for the state's attempts to track sex offenders who have finished their sentences.
Guy Reeves was convicted in January 2006 of taking indecent liberties with a 7-year-old, his third sex-offense conviction. He left jail in May 2007.
The General Assembly passed laws on sex-offender monitoring in 2006 and added specific procedures for the program last December.
Assistant Chatham County District Attorney Marci Trageser argued Tuesday that lawmakers intended the statute to be retroactive as a safety measure for the public and that made tracking part of the original sentence, not additional punishment.
"It clearly specifies in the session law that this is also to apply to any person released from prison," Trageser said.
Baddour's rejection of that argument made Reeves the 29th convicted sex offender in North Carolina to get a tracking device removed.
Last week, another judge ruled that sex offenders shouldn't be subject to lifetime monitoring, and four men have had their monitoring devices removed.
Statewide, 113 people are still monitored. State Department of Correction officials say it costs $2,745 a year to track one offender.
Attorneys opposing the monitoring have argued that the system violates constitutional rights and was beset by technical problems.
"I don't want to make a moral assessment of the thing, (but) it seems to me that, once a person has been either found guilty or pled guilty and has served his sentence and been discharged, then that should be the end of it," said Ken Richardson, the public defender who represents Reeves.
Reeves, who still must stay registered with local authorities as a convicted sex offender, said he was happy he no longer will have to wear a monitoring device.