<P> In New Jersey v. T.L.O. (1985), the Supreme Court ruled that searches in public schools do not require warrants, as long as the searching officers have reasonable grounds for believing that the search will result in the finding of evidence of illegal activity . However, in Safford Unified School District v. Redding (2009), the Court ruled that school officials violated the Fourth Amendment when they strip searched a 13 - year - old girl based only on a student claiming to have received drugs from that student . Similarly, in Samson v. California (2006), the Court ruled that government offices may be searched for evidence of work - related misconduct by government employees on similar grounds . Searches of prison cells are subject to no restraints relating to reasonableness or probable cause . </P> <P> One way courts enforce the Fourth Amendment is through the use of the exclusionary rule . The rule provides that evidence obtained through a violation of the Fourth Amendment is generally not admissible by the prosecution during the defendant's criminal trial . The Court stated in Elkins v. United States (1960) that the rule's function "is to deter--to compel respect for the constitutional guaranty in the only effectively available way--by removing the incentive to disregard it ." </P> <P> The Court adopted the exclusionary rule in Weeks v. United States (1914), prior to which all evidence, no matter how seized, could be admitted in court . In Silverthorne Lumber Co. v. United States (1920) and Nardone v. United States (1939), the Court ruled that leads or other evidence resulting from illegally obtained evidence are also inadmissible in trials . Justice Felix Frankfurter described this secondary evidence in the Nardone decision as the "fruit of the poisonous tree". The Supreme Court rejected incorporating the exclusionary rule by way of the Fourteenth Amendment in Wolf v. Colorado (1949), but Wolf was explicitly overruled in Mapp v. Ohio (1961), making the Fourth Amendment (including the exclusionary rule) applicable in state proceedings . </P> <P> The exclusionary rule and its effectiveness have often been controversial, particularly since its 1961 application to state proceedings . Critics charge that the rule hampers police investigation and can result in freeing guilty parties convicted on reliable evidence; other critics state that the rule has not been successful in deterring illegal police searches . Proponents argue that the number of criminal convictions overturned under the rule has been minimal and that no other effective mechanism exists to enforce the Fourth Amendment . In 1982, California passed a "Victim's Bill of Rights" containing a provision to repeal the exclusionary rule; though the bill could not affect federally mandated rights under the Fourth Amendment, it blocked the state courts from expanding these protections further . </P>

Fourth amendment of the constitution of the united states