A motion to suppress is a motion that revolves around the exclusion of evidence from trial. In the United States, a motion to suppress is a request made by a criminal defendant in advance of a criminal trial asking the court to exclude certain evidence from the trial. The proposed basis for the exclusion must be in the U.S. Constitution, a state constitution, or some specific statute that permits such evidence to be excluded. A motion to exclude evidence that is based on rules of evidence, in advance of the trial, is more commonly called a motion in limine. In federal courts, Rule 41(h) of the Federal Rules of Criminal Procedure governs motions to suppress.
The concept of a motion to suppress is based on the “exclusionary rule.” The exclusionary rule, grounded in the Fourth Amendment, excludes from trial evidence obtained in violation of a defendant’s constitutional rights and protects citizens from unlawful searches and seizures. In Simmons v. United States, the Supreme Court explained, “[i]n order to effectuate the Fourth Amendment's guarantee of freedom from unreasonable searches and seizures, this Court long ago conferred upon defendants in federal prosecutions the right, upon motion and proof, to have excluded from trial evidence which had been secured by means of an unlawful search and seizure.”
[Last updated in June 2021 by the Wex Definitions Team]