Petitioner was convicted of burglary by a Louisiana court and his conviction was affirmed by the highest state court. Thereafter, in Mapp v. Ohio, 367 U.S. 643, this Court held that evidence illegally seized is inadmissible in a state criminal trial, and petitioner applied for a writ of habeas corpus. The writ was denied by the federal District Court and by the Court of Appeals, which found the searches of petitioners person and property illegal but held that the Mapp exclusionary rule was not retrospective. Held: The exclusionary rule announced in Mapp does not apply to state court convictions which had become final before its rendition. Pp. 622-640.

(a) The effect of a subsequent ruling of invalidity on prior final judgments when collaterally attacked is not automatic retroactive invalidity but depends upon a consideration of particular relations and conduct, or rights claimed to have become vested, of status, of prior determinations deemed to have finality, and of public policy in the light of the nature of the statute and its previous application. Chicot Drainage Dist. v. Baxter State Bank, 308 U.S. 371. P. 627.

(b) No distinction is drawn between civil and criminal litigation. P. 627.

(c) The Constitution neither prohibits nor requires retroactive effect and in each case the Court determines whether retroactive or prospective application is appropriate. This approach is particularly correct with reference to the unreasonable search and seizure proscription of the Fourth Amendment. P. 629.

(d) The primary purpose of Mapp v. Ohio was the enforcement of the Fourth Amendment through the inclusion of the exclusionary rule within its rights, and this purpose would not be advanced by making the rule retroactive. Pp. 636-637.

(e) Other areas in which rules have been applied retrospectively concerned the fairness of the trial, which is not under attack here. P. 639. [381 U.S. 618, 619]

(f) The date of the seizure in Mapp (which preceded that here) is of no legal significance; the crucial date is the date of the Mapp judgment which changed the rule. P. 639.

Euel A. Screws, Jr., argued the cause for petitioner. With him on the brief was Truman Hobbs.

Teddy W. Airhart, Jr., Assistant Attorney General of Louisiana, argued the cause for respondent. With him on the brief was Jack P. F. Gremillion, Attorney General.

H. Richard Uviller argued the cause for the National District Attorneys Association, as amicus curiae, urging affirmance. With him on the brief was Michael Juviler. Louis J. Lefkowitz, Attorney General of New York, Samuel A. Hirshowitz, First Assistant Attorney General, Barry Mahoney and Thomas F. OHare, Jr., Assistant Attorneys General, H. Richard Uviller and Michael Juviler filed a supplementary memorandum on behalf of the National District Attorneys Association, as amicus curiae.

MR. JUSTICE CLARK delivered the opinion of the Court.

In Mapp v. Ohio, 367 U.S. 643 (1961), we held that the exclusion of evidence seized in violation of the search and seizure provisions of the Fourth Amendment was required of the States by the Due Process Clause of the Fourteenth Amendment. In so doing we overruled Wolf v. Colorado, 338 U.S. 25 (1949), to the extent that it failed to apply the exclusionary rule to the States.1 This case presents the question of whether this requirement operates retrospectively upon cases finally decided in the [381 U.S. 618, 620] period prior to Mapp. The Court of Appeals for the Fifth Circuit held that it did not, 323 F.2d 11, and we granted certiorari in order to settle what has become a most troublesome question in the administration of justice.2377 U.S. 930. We agree with the Court of Appeals. [381 U.S. 618, 621]

The petitioner was convicted in a Louisiana District Court on May 28, 1959, of "simple burglary." At the time of his arrest he had been under surveillance f