Criminal justice is the system of practices and institutions of government directed at upholding social control, deterring and mitigating crime, or sanctioning those who violate laws with criminal penalties and rehabilitation efforts. Those accused of crime have protection against abuse of investigatory and prosecution powers.

^{___________________________________________________________________________________________________________________________________________}

^{The History of Criminal Justice}

The modern criminal justice system has evolved since ancient times, with new forms of punishment, added rights for offenders and victims, and policing reforms. These developments have reflected changing customs, political ideals, and economic conditions. In ancient times through the Middle Ages, exile was a common form of punishment. During the Middle Ages, payment to the victim (or the victim's family), known as wergild, was another common punishment, including for violent crimes. For those who could not afford to buy their way out of punishment, harsh penalties included various forms of corporal punishment. These included mutilation, branding, and flogging, as well as execution.

Though a prison, Le Stinche, existed as early as the 14th century in Florence, Italy,[19] incarceration was not widely used until the 19th century. Correctional reform in the United States was first initiated by William Penn, towards the end of the 17th century. For a time, Pennsylvania's criminal code was revised to forbid torture and other forms of cruel punishment, with jails and prisons replacing corporal punishment. These reforms were reverted, upon Penn's death in 1718. Under pressure from a group of Quakers, these reforms were revived in Pennsylvania toward the end of the 18th century, and led to a marked drop in Pennsylvania's crime rate. Patrick Colquhoun, Henry Fielding and others led significant reforms during the late eighteenth and early nineteenth centuries.