Targeting such juvenile offenders will make little or no impact on the crime rate, the independent Policy Studies Institute concluded.
The research - involving 531 young people who on average had been arrested four or five times during 1992 - confirmed previous studies showing that most came from chaotic family backgrounds. Half had had contact with social services and about 50 had passed through about 10 care placements.
Over 200 had needed psychiatric help and many regularly truanted, or were disruptive at school, with poor levels of achievement.
Many were experienced users of both alcohol and a variety of drugs. In one case, Nick, aged 13, who had been detained in a local authority secure unit, said he had used amphetamines, hallucinogens, ecstacy and crack. He drank approximately a dozen bottles of cider a week.
He was unconcerned about his poor schoolwork and had truanted from the age of 12, when he would commit crimes. He did not think anything would stop him offending - not even the threat of prison.
Although he had reported he had good relationships with his parents, he was on the local authority child protection register and had, in the past 18 months, four placements with foster parents and in children's homes.
His was one of several cases highlighted as typical by the researchers. But they say the difficulty for the Government is identifying such persistent offenders. They do not all follow the same pattern and using different criteria will identify different children.
In any event the study found that children were at their most 'persistent' in terms of committing crime for only relatively short periods (often no more than six months and rarely more than a year).
Tim Newburn, co-author of the report, said: 'This research shows that there are no simple solutions to the problems of dealing with persistent young offenders. The research casts doubt on the usefulness of the proposed secure training order and should make policymakers question whether custodial sentences will have any significant impact on juvenile crime.'
The costs of building the proposed units at pounds 40m, plus pounds 2,000 a week to detain each child, would be better spent on community punishments and efforts to tackle the behaviour of the children, who generally require intensive therapy.
Persistent Young Offenders; PSI; available from BEBC Distribution Ltd, PO Box 1496, Poole, Dorset, BH12 3XD; pounds 15.Reuse content