What is the "exclusionary rule"?

The "exclusionary rule" is a legal principle that prevents the use of evidence obtained in violation of a person's constitutional rights, particularly those protected by the Fourth Amendment, which guards against unreasonable searches and seizures. When law enforcement officials conduct searches or gather evidence without proper warrants or probable cause, such evidence cannot be used in court. This rule serves to deter police misconduct and protect the integrity of the judicial process by ensuring that only evidence gathered lawfully is admissible in trials.

This principle is essential in maintaining public trust in the legal system, as it removes incentives for law enforcement to flout constitutional protections. The exclusionary rule has substantial case law backing it, having been established in landmark Supreme Court cases such as Mapp v. Ohio, which extended the exclusionary rule to state courts. Understanding this rule is crucial for law enforcement professionals as it shapes how they conduct investigations and the procedures they must follow to ensure that evidence is collected legally.