Criminal Procedure is the laws and rules governing the mechanisms under which crimes are investigated, prosecuted, adjudicated, and punished. It gives in detail the procedure that is to be followed beginning with the initial investigation of the crime and concluding with the acquittal or imposition of punishment pursuant to conviction.
Criminal procedures safeguards against indiscriminate application of criminal laws and ill treatment of suspected criminals. Criminal procedure tries to ensure that their constitutional rights, beginning with their initial encounter with the police through arrest investigation, trial, sentencing, and appeals, are not violated.
States and the Federal government have their own criminal codes, defining the types of conduct that constitutes crimes. Most of the state codes of criminal procedure closely model the Federal Rules of Criminal Procedure.
A few of the rights the U.S Constitution provides to criminal defendants are guarantees of due process and equal protection under the laws, the right to have legal counsel present, the right to confront witnesses, the right to a jury trial, and the right to not testify against oneself. While the State Constitutions and procedural rules can increase the protection afforded to criminal defendants, they cannot offer less protection than those guaranteed by the U.S. Constitution.