Aim To examine the linkage between bullying behaviour in early childhood and any subsequent contact with the criminal justice system.

Methods A Canadian sample (570 boys and 379 girls) was derived from clients who participated in the evidenced-based programme, SNAP® (STOP NOW AND PLAN), between 2001 and 2009. A court order was obtained to access any criminal record data on participants. The Early Assessment Risk Lists (EARL-20B and EARL-21G) and the Child Behavior Checklist (CBCL) were used to identify level of risk and bullying behaviour. Outcome variables included age the child first came in contact with the criminal justice system and frequency.

Results Logistic and Cox regression analyses indicate that the risk of onset of criminal offence for bullies was significantly higher than for non-bullies. The hazard of criminal offence for bullies is 1.9 times (95% CI: 1.1–3.2) than that of non-bullies. This holds true even when adjusted for age, gender and other risk factors.

Conclusion We found a strong linkage between bullying behaviour during childhood and subsequent criminal offending after the age of 12. Criminal convictions for bullies were nearly twice as high for non-bullies up to the child's 18th birthday. EARLs were effective in differentiating risk associated with bullying. Copyright © 2011 John Wiley & Sons, Ltd.