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 Texas, criminal procedure is governed by both state and federal laws, which outline the processes for investigation, arrest, charging, trial, and the eventual conviction or acquittal of individuals accused of crimes. The Texas Code of Criminal Procedure contains the rules that law enforcement, prosecutors, and courts must follow to ensure a fair and constitutional process for the accused. This includes procedures for obtaining warrants, conducting searches and seizures, the arraignment process, pretrial motions, trial, sentencing, and appeals. Additionally, the U.S. Constitution, particularly the Fourth, Fifth, Sixth, and Fourteenth Amendments, provides protections against unreasonable searches and seizures, self-incrimination, and guarantees the right to a fair trial and due process. Federal and state court opinions interpret these laws and constitutional protections, shaping the application of criminal procedure in Texas. Defendants in criminal proceedings have the right to be represented by an attorney, and if they cannot afford one, the state is generally required to provide legal representation.