Youth offending has fallen for the first time in years in one state, but the drop could be down to juveniles becoming adult criminals rather than tough-on-crime policies.
While Victoria's latest Crime Statistics Agency figures show criminal offences fell 0.2 per cent in the 12 months to the end of March, youth offending dropped by six per cent for the first time in four years.
Victoria Police Deputy Commissioner Bob Hill said he could not put his finger on one issue that had led to the reduction.
"I can't say it's legislation, I can't say whether it's the enforcement activities, the offenders have shifted their thinking, or how they do their business," he said on Thursday.
Asked if youth offenders were ageing out into the adult offenders category, Mr Hill said it was a "fair assumption".