The study examined the juvenile court records for the entire "Class of 1988," that is, all youth in Washington State who turned 18 during 1988. It then tallied their adult criminal court records for the following 7 years until 1995, when they were 25 years old. Under current law, the more serious the crime and the greater the number of prior convictions, the greater the sentence a juvenile offender receives. The study found that of the Class of 1988, both of these factors were strongly predictive of future felony offending as adults. Age, compared to crime and criminal history, played a smaller role in predicting adult felony offending. Although criminal history is a stronger predictor of future criminal behavior, the youth's criminal history is not known until second and subsequent convictions are recorded. Thus, age at first conviction can be a warning signal for future juvenile and adult criminal behavior. Minor juvenile offenders have almost the same low chance of becoming adult felony offenders as do youths without a juvenile court record. A small percentage of juveniles have a much higher chance of offending repeatedly as juveniles. These chronic juvenile offenders have a notably higher chance of becoming adult offenders. After finding ways to identify these high-risk youths, a second challenge is to identify interventions that are cost- effective. It is too early to determine whether the 1994 Washington State law that automatically transfers certain serious juvenile offenders to adult court reduces recidivism. 3 figures