Criminal Procedure Law

Criminal justice systems at the federal, state, and local levels must follow a series of rules governing the stages of a criminal case, beginning with police investigations and continuing all the way through trial and appeal. Federal criminal procedure is governed by substantive criminal laws found in Title 18 of the U.S. Code and the Federal Rules of Criminal Procedure. Every state has its own code of criminal statutes. Procedural rules help ensure that the government applies the law in as consistent a manner as possible, and also help safeguard individuals’ constitutional rights. These procedures apply in all criminal matters, as well as in some quasi-criminal proceedings, such as deportation hearings.

Criminal procedure rules ensure consistency and protect constitutional rights.

Fourth Amendment Rights

The Fourth Amendment to the U.S. Constitution protects people from “unreasonable searches and seizures” by police. In order to prevent violations of this right, police are required to obtain a search warrant from a judge, after showing probable cause to believe the search is likely to produce evidence related to a crime. A defendant who alleges that police seized evidence in violation of his or her Fourth Amendment rights may file a motion to suppress that evidence under the exclusionary rule.

Fifth and Sixth Amendment Rights

A series of constitutional rights, commonly known as Miranda rights, protect people during police investigations and at trial. The right to remain silent, well-known to anyone who watches cop shows on television, means that the police cannot force people to incriminate themselves, and prosecutors cannot call a defendant as a witness at the defendant’s own trial.

A person has the right to an attorney of his or her own choosing once he or she has been arrested and during any custodial interrogation by police. In some situations, a person who cannot afford an attorney has the right to a public defender or a court-appointed lawyer. Once a person has invoked his or her right to silence or to an attorney, all questioning must cease.

Other rights guaranteed by the Fifth and Sixth Amendments include the right to confront one’s accuser in court, known as the Confrontation Clause; the right against being charged with the same offense more than once, known as double jeopardy; the right to a trial before an impartial jury; and the right to a speedy trial without undue delay.

Eighth Amendment Rights

The Eighth Amendment protects people after an arrest, which might be in the early stages of a criminal case, and after a conviction. It prohibits “excessive bail,” which means that while a judge is not obligated to grant bail for a person after his or her arrest, the amount of bail may not be unreasonable or excessive.

US Constitution Annotated

To view the Constitution in its entirety, visit Justia’s US Constitution Annotated.

The Eighth Amendment also prohibits “excessive fines” and “cruel and unusual punishment.” Supreme Court Justice William Brennan identified four principles to consider in determining whether a punishment violates the Eighth Amendment: (1) whether its “severity” is “degrading to human dignity”; (2) whether it is assessed in a “wholly arbitrary fashion;” (3) whether society has generally rejected it as a punishment; and (4) whether it is “patently unnecessary.” Furman v. Georgia, 408 U.S. 238 (1972). That decision ruled that capital punishment violated the Eighth Amendment, but the court reversed that holding four years later in Gregg v. Georgia, 428 U.S. 153 (1976).

Stages of the Criminal Process

After a person has been arrested, the state must formally bring charges, either by filing a complaint or obtaining a grand jury indictment. The court informs the defendant of the charges at the first court appearance, known as an arraignment. Pre-trial proceedings allow the defendant to request suppression of evidence under the exclusionary rule and resolve other matters.

The criminal trial process begins with empaneling a jury, unless the defendant chooses to have a bench trial. The state, which has the burden of proving guilt, presents its evidence and witnesses first. The defendant then has the opportunity to rebut the state’s claims or prove an affirmative defense. The judge or jury determines a verdict. If the jury cannot reach a unanimous verdict, the court may declare a mistrial. If the defendant is found guilty, the court determines a sentence.

Last reviewed October 2023

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