A review of Scotland's record on youth crime has questioned the effectiveness of recent major investment to tackle the problem.
Record investment has failed to cut the numbers of young offenders
Although an extra £100m has been spent to combat youth crime in the last five years, the number of persistent young offenders has continued to rise.
In a new report, Audit Scotland urged the Scottish Executive to take a step back and evaluate the problem.
The executive spent £235m on the issue in 2001 compared with £336m last year.
The Scottish government said changes would be made to the way youth offending was measured and more focus would also be placed on early intervention.
In the past five years, 500 more social workers have been recruited for children, as well as the introduction of a youth crime action plan and Asbos for the under-16s.
Over the same period the number of persistent young offenders has gone up.
Audit Scotland said it was difficult to get clear evidence that the increase in resources has provided value for money or has been used effectively.
The report also found that increases in referrals had put pressure on the children's hearing system
Robert Black, auditor general for Scotland, said: "Youth justice is a complex area.
"It is encouraging that recent initiatives have resulted in some improvements, for example quicker reports from the police, faster decision making by the children's reporter service and better partnership working by the various agencies."
But he added that more effective performance measures "would make it easier to direct resources where they will have greatest impact".
The Liberal Democrat justice spokeswoman, Margaret Smith, called on the new administration to build on the achievements of the previous executive.
She added: "I want to see this strategy include far-reaching policies to relieve the pressure on the children's hearing system, address community concerns about anti-social behaviour and improve life chances for young people across Scotland."
Cosla spokeswoman for education, children and young people, Isabel Hutton, insisted the report showed that resources were being put to good use with practical measures being delivered in a "locally sensitive" manner.
"Having now improved the processes and infrastructure, local authorities will continue to work with other partners towards tangible reductions in youth offending."