An Amsterdam project designed to stop young offenders with convictions for violent crime from committing further serious offences appears to have been a failure, justice ministry research shows. 

The project, launched in 2011, focused on 600 young offenders who were given a combination of punishment and specialist care to keep them out of further trouble. Many have psychological and addiction issues and they often come from unstable backgrounds. 

But the re-offending rate among youngsters on the Top 600 list is actually slightly higher than among those who were not included in the project, researchers from the ministry’s scientific institute WODC say. And, they say, the project should not be expanded until its worth has been proved. 

More than 40 separate organisations, including social workers and educational institutes, have been involved in the project and the methodology is now being used across the country. 

City mayor Femke Halsema described the results as “disappointing” but said it is “too early to draw far-reaching conclusions about the Top 600 method as a whole”. 

The researchers say that one reason that the Top 600 youngsters appear to commit more offences could be because they are more likely to be on the police radar. This would mean they are more likely to be caught and convicted than the control group.  

The researchers also say that the project may have aimed “too high” in trying to reduce the re-offending rate for a group of youngsters “with problems in so many areas and with reduced capacities and motivation”. 

The WODC only looked at the re-offending rate, not at the impact on young family members and on improving opportunities – the two other aims of the project. 

Justice minister Dilan Yesilgöz said her department would study the recommendations closely and would brief parliament shortly on follow-up steps.