Criminal procedure is the process related to the investigation, arrest, charging, and conviction or acquittal of a criminal defendant. Much of criminal procedure is comprised of processes and rules through which the government (state, federal, or municipal) enforces substantive criminal law and through which a criminal defendant’s Constitutional and other rights are protected.

The law of criminal procedure is primarily located in the applicable state or federal rules of criminal procedure and state and federal court opinions interpreting and applying Constitutional and other legal rights.

In Arkansas, criminal procedure is governed by both state statutes and the Arkansas Rules of Criminal Procedure. These rules outline the steps and processes from the initial investigation of a crime to the arrest, charging, trial, and potential conviction or acquittal of a defendant. The procedures are designed to enforce the state's substantive criminal law while also safeguarding the constitutional rights of defendants, such as the right to a fair trial, the right to counsel, and protection against self-incrimination and unreasonable searches and seizures. Federal laws and constitutional protections, including those found in the U.S. Constitution's Fourth, Fifth, Sixth, and Fourteenth Amendments, also apply to criminal proceedings in Arkansas. State and federal court opinions further interpret these laws and rights, providing precedents that guide the application of criminal procedure in Arkansas courts.