Examine the field of criminal justice in the United States, which involves the investigation of criminal activity and the procedures necessary to the prosecution and conviction of crimes. Criminal justice activities include gathering evidence, arresting suspects, bringing charges, conducting trials, sentencing the convicted, and carrying out punishment.
To this end, the criminal justice system involves law enforcement agencies charged with the prevention of crime and the apprehension of criminal offenders; court bureaucracies charged with determining the innocence or guilt of accused offenders and with the sentencing of convicted criminals; and the network of corrections institutions charged with the control, custody, supervision, and treatment of those convicted of a crime, including probation and parole agencies for when a prisoner is released after serving a sentence. Other important figures are the prosecutor, who makes the case to convict the defendant, and the defense attorney, who makes the case to exonerate the defendant. Police officers are the most public law-enforcement agents, responsible for crime prevention and investigation.
Crimes in the United States can be prosecuted in federal, state, or military criminal justice systems. The U.S. Department of Justice is a federal executive department of the U.S. government, responsible for enforcement of federal laws; the Federal Bureau of Investigation is the principal federal law enforcement agency. At the state level, each state has separate judicial systems for adults and juveniles. Some trials involve juries (a group of citizens specially commissioned to render a verdict), and others are determined by a judge (known as a bench trial). Those found guilty of committing a crime can receive a variety of sentences, depending on the severity of the crime, ranging from fines and community service to prison time or even the death penalty where it is legal. Some states do not allow for the death penalty to be imposed.