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, he can rule that it not be shown in court. It could also refer to a prosecutor improperly or intentionally hiding evidence that he or she 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. This can result in a mistrial in the latter case and/or the dismissal of the prosecutor.
If the discovery of an item(s) was obtained by illegal means, it may still be allowed into evidence under some circumstances. These exceptions include:
- Inevitable discovery - if discovery of the evidence was inevitable via purely legal means
- Independent source - if the discovery involved a combination of legal and illegal means, but the illegality was of marginal significance, such that the evidence could have been discovered based on the legal source alone
- Standing - the violation affects the rights of someone other than the defendant, and the defendant does not have standing to complain
- Good faith - the illegality is not the fault of the law enforcement officers who obtained the evidence, who did so pursuant to a facially valid warrant granted by a neutral and detached magistrate.
- Attenuation - If the relationship between the illegality and the nature of the evidence obtained is reduced sufficiently for the evidence to be considered untainted (e.g., use of a booking photo from an unlawful arrest to identify the defendant in a lineup)
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.