Suppression of evidence


Suppression of evidence is a term used in the United States legal system to describe the lawful or unlawful act of preventing evidence from being shown in a trial. This could happen for several reasons. For example, if a judge believes that the evidence in question was obtained illegally, the judge can rule that it not be shown in court. It could also refer to a prosecutor improperly or intentionally hiding evidence that does not go with their case and could suggest or prove to the judge or jury that the defendant is not guilty or that he is legally obligated to show the defense. In the latter case, this would be a violation of the 5th amendment to the United States Constitution. Also Rule 3.8 of the ABA Model Rules of Professional Conduct requires prosecutors to "make timely disclosure to the defense of all evidence or information that tends to negate the guilt of the accused or mitigates the offense." This can result in a mistrial in the latter case and/or the dismissal of the prosecutor.

Motion to suppress

In common law legal systems, a motion to suppress is a formal, written request to a judge for an order that certain evidence be excluded from consideration by the judge or jury at trial. In the United States, the term "motion to suppress" typically encompasses motions in criminal cases where the proposed basis for exclusion arises from the United States Constitution, a state constitution, or a specific statute permitting the exclusion of certain types of evidence.
A motion to exclude evidence where the proposed basis for exclusion arises from the rules of evidence is more commonly termed a motion in limine.

United States Law

In the United States, the motion to suppress stems from the exclusionary rule. As the U.S. Supreme Court stated in Simmons v. United States: "In 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."
Because it is grounded in the right to be secure from unreasonable searches and seizures, a person must have standing to move to suppress evidence. In other words, one cannot object to evidence obtained by an illegal search if it was someone else's privacy that was violated.
On a federal level, a motion to suppress is set down in Rule 41 of the Federal Rules of Criminal Procedure.

Exceptions

If the discovery of an item was obtained by illegal means, it may still be allowed into evidence under some circumstances. These exceptions include:
Evidence obtained as a result of Miranda violations is also subject to special analysis, depending on whether the statement is deemed voluntary or coerced, not merely whether police provided the appropriate warnings.