A custodial sentence that may be passed on a person aged 12 or over but under 17 (see juvenile offender). The offence must be such that it would be punishable by imprisonment if committed by an adult. The minimum detention period for the order is 4 months and the maximum period is 2 years. Normally, half the sentence is served in detention and half in the community under the supervision of a probation officer or other responsible person. DTOs replaced secure training orders (for 12–14 year olds) and detention in a young offender institution (for 15–17 year olds) in 2000.