Three custodial options are house arrest or home detention, electronic monitoring, and intensive supervision probation. House arrest limits the geographic freedom of individuals to their residences during specific periods of time. Despite growing acceptance of the house arrest concept, however, some urge caution since the conversion of a home into a prison can have a negative impact on spouses, children, visitors, and neighbors. The basic idea of electronic monitoring is to divert offenders from incarceration and confine them in their residences during specified hours, typically evenings and weekends. Monitoring devices are of two main types. In one type, offenders are required to wear a small transmitter strapped to the wrist or ankle which emits an encoded signal to a receiver-dialer unit attached to their phone, which in turn is connected to a central computer. In another type, an encoder device is strapped to offenders with a verifier box attached to their phone. Random calls are made to the offender's phone by the computer, and offenders must identify themselves and insert the encoder device into the verifier box. Intensive supervision probation is based on control, close surveillance, containment, and community safety. Because 11 percent of the New Zealand prison population is made up of remand inmates who have not been convicted or sentenced, and many do not ultimately receive a prison sentence, the three custodial options may be useful in dealing with many offenders. 4 references.