Prosecutors will be able to request that sex offenders who were not already given an electronic anklet be electronically tagged after a legal revision takes effect Friday.

The revision allows authorities to retroactively apply the anklet to criminals convicted before the law took effect in 2008.

Prosecutors may now request that the court place the device on convicted sex offenders within three years of their release, should they believe there is a risk of a repeat offense. The maximum period has also been raised from 10 to 30 years.

A total of 6,916 sex offenders could be tagged under the law, according to the Justice Ministry and the Supreme Prosecutor’s Office.

Prosecutors will select those who committed more than two offenses or abused a victim yonger than 13 and will request a court order to place an anklet on them, said officials.

The revision to the electronic anklet law was made in March following a series of high-profile sex crimes against children.

“Though we will take every precaution in enforcing the revised law, we plan to respond forcefully to sex offenders with the electronic anklet, which is one of the best measures against sex criminals,” said a prosecution official.

The average repeat offense rate of offenders is 14.8 percent, which the official said added to the argument for the traceable anklet system to be reinforced.

The Supreme Prosecutor’s Office established last week a set of guidelines on the selection and processes of the retroactive anklet sentence, which will be sent out to all 57 prosecutorial offices nationwide, said officials.

Some, however, argue that the anklet is not the answer.

Earlier this year, a convicted rapist cut off his anklet and escaped, though he did not commit any other offense before he was apprehended.

The ministry will introduce stronger anklets by the end of August, said officials.

The new law has met some criticism for the retroactive application of the anklet system.

By Bae Hyun-jung (tellme@heraldcorp.com)