Juvenile offenders are often administered actuarial risk assessment measures in order to classify them in terms of their recidivism risk. In the interest of public safety and seeking the best treatment for juvenile offenders, it is crucial that the assessment instruments used with juvenile offenders actually measure what they purport to measure. The results of two studies of the NCAR reliability and validity are presented here. The first study assessed the inter-rater reliability of the NCAR by having 175 court counselors score the NCAR based on videotaped vignettes of juvenile offenders. Results indicated that the inter-rater reliability of the NCAR was superior when compared to clinical judgment. The second study assessed the predictive validity of the NCAR by following a statewide sample of 464 juvenile offenders over the course of 12 months. Results revealed that risk scores derived from the NCAR were significantly correlated with rearrest. However, variation in the relationship between risk scores and rearrest were observed for subgroups based on gender and race/ethnicity, indicating needed improvement on the NCAR. Thus, although challenges remain, the findings show that actuarial risk assessment for juvenile offenders can reliably and accurately estimate the risk for reoffending among this population of offenders. Tables, figures, references, appendix