The Vinson Court ruled in Wolf v. Colorado (1949) that the exclusionary rule was not constitutionally required in state court proceedings. The exclusionary rule had applied in federal court proceedings since Weeks v. United States (1914). However, Justice Felix Frankfurter reasoned that the rule was not mandated for states in part because thirty states did not require adherence to the exclusionary rule. “We cannot brush aside the experience of States which deem the incidence of such conduct by the police too slight to call for a deterrent remedy not by way of disciplinary measures but by overriding the relevant rules of evidence,” he wrote.

In his concurring opinion, Justice Hugo Black referred to the exclusionary rule as a “judicially created rule of evidence.” Justice Frank Murphy wrote a dissenting opinion, arguing that the exclusionary rule was the only effective deterrent to unlawful police conduct: “The conclusion is inescapable that but one remedy exists to deter violations of the search and seizure clause. That is the rule which excludes illegally obtained evidence. Only by exclusion can we impress upon the zealous prosecutor that violation of the Constitution will do him no good.”

The Warren Court overruled Wolf v. Colorado in Mapp v. Ohio (1961).