"criminal justice, interdisciplinary academic study of the police,
criminal courts, correctional institutions (e.g., prisons),
and juvenile justice agencies, as well as of the
agents who operate within these institutions. Criminal justice is distinct from
criminal law, which defines the specific behaviours that
are prohibited by and punishable under law, and from criminology, which is the scientific study of the
nonlegal aspects of crime and delinquency, including their causes, correction, and
prevention.
The field of criminal justice emerged in the United States in the second half of the 20th century. As the Supreme Court of the United States gradually expanded the rights of criminal defendants on the basis of the due process clause of the U.S. Constitution, the gap between the actual performance of criminal justice agencies and what was legally required and legitimately expected of them began to grow."
The Criminal Justice by 
