Analysis of recidivism of juvenile delinquents released from a juvenile classification home: Building risk assessment instruments for juvenile delinquents

Abstract

The creation of structured risk assessment instruments to support judicial decision making has been an important issue in the juvenile justice systems of Japan. We analyzed the recidivism of 1,080 delinquents who were released from a Juvenile Classification Home. The recidivism risk factors were separated into seven categories such as antisocial attitudes and substance abuse, and a survival analysis based on Cox's proportional hazard model was performed for each of the categories to determine which factors affected recidivism. From the results of these analyses, many static and dynamic factors were identified as factors affecting risk. Furthermore, a prototype for risk assessment was created from the 19 risk factors obtained by analyzing all categories, which enabled accuracy to be obtained above a certain level. This research has shown that it should be possible to build a practical and accurate risk assessment for Japan by including an even wider range of risk factors based on this research.