Mr. Chief Justice Warren
delivered the opinion of the Court.
Petitioner waived trial by jury and was convicted in a Connecticut state court of wilfully injuring a public building in violation of Connecticut General Statutes § 53-45 (a). Specifically, petitioner and his codefendant Arnold were found guilty of having painted swastikas on a Norwalk, Connecticut, synagogue. The trial took place before our decision in Mapp v. Ohio, 367 U. S. 643, but the conviction was affirmed on appeal after that decision. Connecticut v. Fahy, 149 Conn. 577, 183 A. 2d 256 (1962). At the trial of the case, a can of black paint and a paint brush were admitted into evidence over petitioner’s objection. On appeal, the Connecticut Supreme Court of Errors held that the paint and brush had been obtained by means of an illegal search and seizure. It further held that the Mapp decision applies to cases pending on appeal in Connecticut courts at the time that decision was rendered, and, therefore, the trial court erred in admitting the paint and brush into evidence. However, the court affirmed petitioner’s conviction because it found the admission of the unconstitutionally obtained evidence to have been harmless error. We granted certiorari, 372 U. S. 928 (1963).
On the facts of this case, it is not now necessary for us to decide whether the erroneous admission of evidence obtained by an illegal search and seizure can ever be subject to the normal rules of “harmless error” under the federal standard of what constitutes harmless error. Compare Ker v. California, 374 U. S. 23. We find that the erroneous admission of this unconstitutionally obtained evidence at this petitioner’s trial was prejudicial; therefore, the error was not harmless, and the conviction must be reversed. We are not concerned here with whether there was sufficient evidence on which the petitioner could have been convicted without the evidence complained of. The question is whether there is a reasonable possibility that the evidence complained of might have contributed to the conviction. To decide this question, it is necessary to review the facts of the case and the evidence adduced at trial.
On February 1, 1960, between the hours of 4 and 5 a. m., swastikas were painted with black paint on the steps and walls of a Norwalk synagogue. At about 4:40 a. m., Officer Lindwall of the Norwalk police saw an automobile being operated without lights about a block from the synagogue. Upon stopping the car, Lindwall found that Fahy was driving and Arnold was a passenger. Lindwall questioned Fahy and Arnold about their reason for being out at that hour, and they told him they had been to a diner for coffee and were going home. Lindwall also checked the car and found a can of black paint and a paint brush under the front seat. Having no reason to do otherwise, Lindwall released Fahy and Arnold. He followed the car to Fahy’s home. Later the same morning, Lindwall learned of the painting of the swastikas. Thereupon, he went to Fahy’s home and — without having applied for or obtained an arrest or search warrant— entered the garage under the house and removed from Fahy’s car the can of paint and the brush. About two hours later, Lindwall returned to the Fahy home, this time in the company of two other Norwalk policemen. Pursuant to a valid arrest warrant, the officers arrested Fahy and Arnold.
At trial, the court admitted the paint and brush into evidence over petitioner’s objection. We assume, as did the Connecticut Supreme Court of Errors, that doing so was error because this evidence was obtained by an illegal search and seizure and was thus inadmissible under the rule of Mapp v. Ohio. Examining the effect of this evidence upon the other evidence adduced at trial and upon the conduct of the defense, we find inescapable the conclusion that the trial court’s error was prejudicial and cannot be called harmless.
Obviously, the tangible evidence of the paint and brush was itself incriminating. In addition, it was used to corroborate the testimony of Officer Lindwall as to the presence of petitioner near the scene of the crime at about the time it was committed and as to the presence of a can of paint and a brush in petitioner’s car at that time. When Officer Lindwall testified at trial concerning that incident, the following transpired:
“Q. Will you tell the Court what you found in the car?
“A. Checking on the passengers’ side, under the front seat I found a small jar of paint and a paint brush.
“Q. Are you able to identify this object I show you?
“A. Yes.
“Q. What is it?
“A. A jar of paint I found in the motor vehicle.
“Q. I show you this object and ask you if you can identify that.
“A. Yes, sir.
“Q. What is it?
“A. A paint brush.
“Q. Where did you first see this paint brush?
“A. Under the front seat of Mr. Fahy’s car.”
The brush and paint were offered in evidence and were received over petitioner’s objection. The trial court found: “13. The police found the same can of black paint and the brush in the car which the defendants had been operating when stopped by Officer Lindwall earlier in the morning.” It can be inferred from this that the admission of the illegally seized evidence made Lindwall’s testimony far more damaging than it would otherwise have been.
In addition, the illegally obtained evidence was used as the basis of opinion testimony to the effect that the paint and brush matched the markings on the synagogue, thus forging another link between the accused and the crime charged. At trial, Norwalk Police Officer Tigano testified that he had examined the markings on the synagogue and had determined that they were put on with,black paint. He further testified that he had examined the contents of the can illegally seized from Fahy’s car and had determined that it contained black paint. Even more damaging was Tigano’s testimony that he had taken the illegally seized brush to the synagogue “to measure the width of the brush with the width of the paintings of the swastikas.” Over objection, Tigano then testified that the brush “fitted the same as the paint brush in some drawings of the lines and some it did not due to the fact the paint dripped.” Thus the trial court found: “14. The two-inch paint brush matched the markings made with black paint upon the synagogue.” In relation to this testimony, the prejudicial effect of admitting the illegally obtained evidence is obvious.
Other incriminating evidence admitted at trial concerned admissions petitioner made when he was arrested and a full confession made at the police station later. Testifying at trial, Norwalk Police Lieutenant Virgulak recounted what took place when Fahy, who was just waking up at the time, was arrested:
“I told him I [sic, he] was under arrest for painting swastikas on the synagogue. He said, 'Oh, that?’ and he appeared to lay back in bed.
“Q. Did you have any further conversation with Fahy before you reached the police station that you remember?
“A. I asked him what the reason was for painting the swastikas and he said it was only a prank and I asked him why and he said for kicks.”
At the police station, there was further questioning, and Fahy told Lieutenant Virgulak that he, Fahy, would take the responsibility for painting the swastikas. In addition, some hours after the arrest Arnold was asked to give a statement of the events, and he complied, dictating a complete confession of two typewritten pages. After this confession was admitted against Arnold at trial, Lieutenant Virgulak testified that he had read the confession to Fahy and:
“Q. After you finished reading it, will you tell us whether or not he [Fahy] made any comment?
“A. I asked him what his version was and he said the story was as I had it from Mr. Arnold. I asked him if he would like to give a written statement and he declined.”
The record does not show whether Fahy knew that the police had seized the paint and brush before he made his admissions at the time of arrest and en route to the police station. In oral argument, however, counsel for the State told the Court that Fahy “probably” had been told of the search and seizure by then. Of course, the full confession was more damaging to the defendants, and unquestionably the defendants knew the police-had obtained the paint and brush by the time they confessed. But the defendants were not allowed to pursue the illegal search and seizure inquiry at trial, because, at the time of trial, the exclusionary rule was not applied in Connecticut state courts. Thus petitioner was unable to claim at trial that the illegally seized evidence induced his admissions and confession. Petitioner has told the Court that he would so claim were he allowed to challenge the search and seizure as illegal at a new trial. And we think that such a line of inquiry is permissible. As the Court has noted in the past: “The essence of a provision forbidding the acquisition of evidence in a certain way is that not merely evidence so acquired shall not be used before the Court but that it shall not be used at all.” See Silverthorne Lumber Co. v. United States, 251 U. S. 385, 392; see also Nardone v. United States, 308 U. S. 338; Wong Sun v. United States, 371 U. S. 471. Thus petitioner should have had a chance to show that his admissions were induced by being confronted with the illegally seized evidence.
Nor can we ignore the cumulative prejudicial effect of this evidence upon the conduct of the defense at trial. It was only after admission of the paint and brush and only after their subsequent use to corroborate other state’s evidence and only after introduction of the confession that the defendants took the stand, admitted their acts, and tried to establish that the nature of those acts was not within the scope of the felony statute under which the defendants had been charged. We do not mean to suggest that petitioner has presented any valid claim based on the privilege against self-incrimination. We merely note this course of events as another indication of the prejudicial effect of the erroneously admitted evidence.
From the foregoing it clearly appears that the erroneous admission of this illegally obtained evidence was prejudicial to petitioner and hence it cannot be called harmless error. Therefore, the conviction is reversed, and the cause is remanded for proceedings not inconsistent with this opinion.
It is so ordered.
Arnold was tried and convicted with petitioner Fahy, and their appeals were heard and decided together. Arnold also filed a petition for certiorari; however, that petition was dismissed on Arnold’s motion before we granted Fahy’s petition.
Connecticut’s statutory harmless error rule states that the Supreme Court of Errors need not reverse a judgment below if it finds the errors complained of “have not materially injured the appellant.” Connecticut General Statutes §52-265 (1958).
The Connecticut Supreme Court of Errors rejected petitioner’s argument that painting swastikas on a synagogue was “defacement,” not “injury,” to a public building. The statute involved was passed in 1832 and made it illegal to “injure or deface” a public building. In 1875, the words “or deface” were omitted, and the statute remained essentially unchanged thereafter. The Connecticut Supreme Court of Errors held that “injure” includes defacement and thus includes petitioner’s acts.