Trying serious or chronic juvenile offenders in criminal court and then incarcerating them in adult correctional facilities raises the question of the extent to which those actions promote or retard community protection and the development of juvenile offenders' accountability and competencies. The article reviews research on the deterrence effect of transfer laws, conviction and sentencing, and recidivism in juvenile versus criminal court, and conditions and programming in juvenile versus adult correctional facilities. While there is some research on the effects of transfer on recidivism, there is virtually no research on the other psychological and behavioral effects on juveniles of prosecution and incarceration in the adult criminal justice system. Such research is critical for informing policy and practice concerning whether juveniles should be incarcerated in adult facilities and, if so, how those facilities can best serve the juveniles under their care. Tables, references, notes