Does the exclusionary rule at trial and on appeal apply to search and seizure claims of state prisoners?

The majority in Stone v. Powell, supra, further found that while the goal of deterrence of law enforcement officials from the violation of Fourth Amendment rights supports the implementation of the exclusionary rule at trial and on direct appeal of state court convictions, "the additional contribution, if any, of the consideration of search-and-seizure claims of state prisoners on collateral review is small in relation to the costs." Id. at 493, 96 S.Ct. at 3051. The costs include intrusions on limited judicial resources, undermining the necessary principle of finality in criminal trials, heightening of friction between the federal and state systems of justice and erosion of the doctrine of federalism. ⁷ See id. at 491 n. 31, 96 S.Ct. 3037. The cost is particularly high because the exclusionary rule "deflects the truthfinding process and often frees the guilty." Id. at 490, 96 S.Ct. at 3050.