Electric Monitoring as a type of probation is the system to monitor criminals all the time using electric devices. As a substitute of custody, minor offenders, parolees, juveniles, and the reprieves live a place of residence or a setting place instead of serving in a correctional institution. This system started some states in US in 1980's has spread all over the states in US now. In Europe, Sweden, the Netherlands, Scotland, England, Spain, and Belgium are operating the system in effect and Germany, France, Italy, and Portugal are introducing the system in a part of its region. Also, Singapore is the only country in Asia to put the system in operation and Australia and New Zealand are enforcing it.

The system is conducted assuming that prior consent of probationers and burden of expense of electric monitoring. The main operating body is Private Corporations acquiring government's approval.

The biggest reason to introduce the system is to reduce operating cost and to settle overcrowding of prisons. In the US, the cost is about $75 to detain a criminal a day. However, it only needs about $5 ~ $25 according to programs when we introduce this system.

Another reason is to enable minor offenders to maintain home by living a community and a workplace, resulting in increasing effects of correction.

Now we expect to introduce this system soon because private prisons are introduced from 2005 in Korea.

The basic way is that a criminal wears the Electric Transmission Device on his wrist or ankle for 24 hours. This Electric Transmission Device transmits its ID number to the Receiver installed in the house every 30 second. The Receiver transmits this signal to the Monitor Station through a telephone wire.

At this time, the signal is related to regular things such as time of home coming, working time, and time of outing. And if the signal is deviate from regularity or it senses a disorder of devices, the signal is sent to the Monitor Station immediately, making an agent of the Monitor Station notify it to monitoring agents of the region. Watching agents in the Monitor Station keep monitoring for 24 hours. And the Monitor Station reports daily monitoring reports to the Probation Center.

As devices, there are Transmitter in the Electric Transmission Device attached to a criminal; the Receiver that sends a signal received from the transmission device to the Monitor Station; the Verifier that identifies criminal; and the Alcohol Measurer detecting the state of drinking. As devices of the Monitor Station, there are the central computer, 24-hour monitoring agents, and daily observation reporting, and so on.