ICJIA staff researched the mental health screening and assessment practices for juvenile police, probation and court services departments, and detention and correctional facilities in Illinois. Results of the study revealed that few agencies used standardized mental health screening or assessment instruments and few had standard policies and procedures in place to identify mental health needs of system-involved youth. The report also provides overviews of instruments and tools used in Illinois and others available to screen for and assess adolescent mental health issues, including reliability and validity information.