Recent electronic tracker damage case raises concerns over sex offender monitoring
Cho Doo-soon, who raped an 8-year-old girl in 2008, enters the Ministry of Justice’s probation office in Ansan, Gyeonggi Province, Dec. 12, 2020. Yonhap
While more than 5,000 sexual offenders are set to be released over three years starting next year, concerns are rising over a shortage of dedicated staff for post-release monitoring.
The electronic monitoring system meant to prevent repeat crimes is under strain as each staffer’s workload has grown and violations and reoffenses have continued, raising questions about its ability to cope.
According to indictments and court rulings submitted by the Ministry of Justice and the Supreme Court to Rep. Kim Dong-ah of the ruling Democratic Party of Korea (DPK), Wednesday, Cho Doo-soon, who raped an 8-year-old girl in 2008, damaged the external antenna of a home monitoring device at his residence in Ansan, Gyeonggi Province, in June last year.
Cho was sentenced to 12 years in prison and released in 2020. He has since been under intensive 24-hour location monitoring.
According to the ruling, Cho smashed the antenna under the delusion that it was beaming radio waves into his brain. The device’s cellular signal weakened sharply, but a probation officer found the damage only six days later during an inspection inside the residence.
From March to June last year, Cho committed six offenses related to his monitoring device, four of them violations of outing restrictions and two cases of damage to the home monitoring device. In May 2025, he damaged the device’s cover, but the offense was only considered an attempt because the device kept working normally.
The case highlights concerns over staff shortage in monitoring sexual offenders after their release, as each dedicated staffer already supervises more than 20 offenders.
According to data the submitted to the office of Rep. Seo Young-kyo of the DPK, 5,039 sexual offenders are set to be released from next year through 2029. Electronic monitoring is expected to cover 161 of them in 2027, 188 in 2028 and 163 in 2029.
The figures are estimated from those ordered to be monitored as of August this year and could rise with parole and other measures.
Korea introduced electronic monitoring in 2008 to curb crimes with a high risk of recurrence, such as sexual violence. Under the system, offenders wear a device that tracks their location around the clock, and probation officers closely supervise them.
Courts can order offenders to wear the device, including those deemed highly likely to reoffend, those who victimized a minor and those who committed the same type of crime again within 10 years of completing a sentence.
The number of offenders each dedicated staffer supervises rose by more than three, from 17.1 in 2022 to 20.7 last year.
Reoffenses by monitored sexual offenders totaled 24 in 2022, 30 in 2023, 18 in 2024 and 23 last year, and 11 through July this year.
Violations of outing restrictions topped 400 cases a year, with 593 in 2022, 505 in 2023, 444 in 2024 and 451 last year. From 2022 through last year, violations of approach bans numbered six to eight a year, while entry-ban violations numbered six to 11.