Upon his release from custody on federal charges of possession of child pornography, David J. Renz of Cicero, N.Y., was ordered to wear a GPS ankle tracking bracelet as a form of monitoring and supervision.
But it took him less than one minute to disassemble it, take it off his leg, and reassemble it while probation officers remained unaware, authorities said. He had only been wearing the tracking anklet for two months.
Renz, 29, was then allegedly able to leave his home March 14 without detection and abduct Lori Bresnahan, 47, a school librarian, and a 10-year-old girl at a mall in Clay, N.Y.
Renz allegedly bound the woman and raped the girl in the car, state police said. He then drove the car a short distance before allegedly attacking Bresnahan, who died of multiple stab wounds.
Renz, according to police, then fled into the nearby woods, where he was found and arrested. He was charged with first-degree rape, murder and kidnapping, as well as second-degree murder.
Renz's ability to evade his location-monitoring bracelet raises questions about both the security and supervision of the technology.
"We were never alerted that the bracelet was taken off," Chief U.S. Probation Officer Matt Brown told ABCNews.com.
In the federal court system, 51,170 defendants were supervised on pretrial relief in the past 12 months, said a spokesperson for the Administrative Office of the U.S. Courts. Of these cases, nearly 9,000 defendants were placed on electronic monitoring.
"Think of the population we're serving here," said George Drake, president of corrections technology firm Correct Tech LLC. "We're talking about people who are deemed to be acceptable to be released on bond. By definition, these individuals are not the most dangerous people."
Of the decision to supervise Renz through GPS monitoring, Drake said it might have been a bad choice.
"In this case, the U.S. attorney pointed out the bracelet was tampered with at 7:08 p.m. last Thursday evening, and the bracelet circuitry was restored at 7:08 p.m.," said Brown "Obviously, he was able to do this in a very short period of time, so we didn't get an alert from the monitoring company."
"The way these bracelets work is that there is an electronic or fiber optic circuit that runs through the bracelet," said Brown. "As long as it is connected, we know the bracelet is intact, and it's on the person."
Brown said the most common way for someone to disable the tracker is by cutting the strap and then taking the ankle bracelet off. While he could not disclose where Renz left the bracelet when he left his home, he said "nothing has happened like this before."
Brown said Renz disassembled his tracker, which was manufactured by BI Inc., a company that makes offender monitoring technologies. The company has a national contract with the U.S. Probation and Pretrial Services System, he said.
A representative from BI Inc. did not respond to ABC News' requests for comment.
But Drake said the flaw was not with the tracking device nor was it a matter of Renz outsmarting the system. He said the problem stemmed from the protocols of the pretrial unit assigned to monitor Renz.