A man suspected of kidnapping and sexually assaulting a woman in Gwangju last week was wearing an electronic ankle bracelet at the time. A few hours later, the man was involved in a car accident and brought to a police station. He was allowed to leave before the police discovered that he had been wearing an electronic tag and that he was a suspect in a sexual assault that had been reported earlier.

The tracking device attached to the suspect’s electronic ankle bracelet was found discarded in a stream soon afterward. Without the tracking device, the electronic anklet alone cannot indicate the wearer’s whereabouts.

There have been eight confirmed cases of people breaking their electronic tags this year, raising questions about the tracking system’s effectiveness in preventing crimes.

One of the reasons for this is a lack of proper oversight. Earlier this month, a man was charged with kidnapping and sexually assaulting a woman after he got his anklet off. The tag had been modified three times, as the man complained of a swollen ankle, and his neighbors had seen him outside his house late at night on numerous occasions despite a curfew barring him from doing so.

In fact, a report by the Bureau of Audit and Inspection released in January 2013 found that between January 2010 and August 2012, 34 of the 45 people found to have broken the curfew were never referred to the police for investigation.

The model of electronic tag currently in use is easy for the wearer to tamper with. In fact, unless the wearer carries the portable tracking device paired with the bracelet, the authorities cannot trace the offender’s movements. The government has said that it will deploy a single-body bracelet by 2016 to make it more difficult for the wearer to avoid being tracked.

A bigger issue is the lack of supervision. The growing number of people ordered to wear anklets makes it difficult to monitor them all effectively. In June, the government expanded the use of electronic anklets to those who have repeatedly committed robberies ― in addition to those with repeated convictions for sex crimes, kidnapping or murder ― further overloading the monitoring system.

Some 1,700 people were wearing electronic ankle bracelets last year and the figure could reach 2,600 by the end of the year. Yet the increase in the number of people monitoring the devices has lagged behind. There are about 200 monitors, merely double the number since the program was launched in 2008, while the number of people wearing the device has increased 12-fold during the same period.

The Justice Ministry said it would add 200 monitors to the current staff by 2017, but this seems hardly sufficient.

The usefulness of an electronic anklet is as a psychological deterrent. If the device wearers are not penalized for breaking the court orders against them, the bracelet will lose any effect it might have as a deterrent. Without sufficient manpower to monitor the wearers, electronic tags will be of no use in crime prevention.