Mr. Justice Brennan
delivered the opinion of the Court.
This case was argued with United States v. Wade, ante, p. 218, and presents the same alleged constitutional error in the admission in evidence of in-court identifications there considered. In addition, petitioner alleges constitutional errors in the admission in evidence of testimony of some of the witnesses that they also identified him at the lineup, in the admission of handwriting exemplars taken from him after his arrest, and in the admission of out-of-court statements by King, a co-defendant, mentioning petitioner’s part in the crimes, which statements, on the co-defendant’s appeal decided with petitioner’s, were held to have been improperly admitted against the co-defendant. Finally, he alleges that his Fourth Amendment rights were violated by a police seizure of photographs of him from his locked apartment after entry without a search warrant, and the admission of testimony of witnesses that they identified him from those photographs within hours after the crime.
Petitioner was convicted in the Superior Court of California of the armed robbery of the Mutual Savings and Loan Association of Alhambra and the murder of a police officer who entered during the course of the robbery. There were separate guilt and penalty stages of the trial before the same jury, which rendered a guilty verdict and imposed the death penalty. The California Supreme Court affirmed, 63 Cal. 2d 690, 408 P. 2d 365. We granted certiorari, 384 U. S. 985, and set the case for argument with Wade and with Stovall v. Denno, post, p. 293. If our holding today in Wade is applied to this case, the issue whether admission of the in-court and lineup identifications is constitutional error which requires a new trial could be resolved on this record only after further proceedings in the California courts. We must therefore first determine whether petitioner’s other contentions warrant any greater relief.
I.
The HandwRiting Exemplars.
Petitioner was arrested in Philadelphia by an FBI agent and refused to answer questions about the Alhambra robbery without the advice of counsel. He later did answer questions of another agent about some Philadelphia robberies in which the robber used a handwritten note demanding that money be handed over to him, and during that interrogation gave the agent the handwriting-exemplars. They were admitted in evidence at trial over objection that they were obtained in violation of petitioner’s Fifth and Sixth Amendment rights. The California Supreme Court upheld admission of the exemplars on the sole ground that petitioner had waived any rights that he might have had not to furnish them. “[The agent] did not tell Gilbert that the exemplars would not be used in any other investigation. Thus, even if Gilbert believed that his exemplars would not be used in California, it does not appear that the authorities improperly induced such belief.” 63 Cal. 2d, at 708, 408 P. 2d, at 376. The court did not, therefore, decide petitioner’s constitutional claims.
We pass the question of waiver since we conclude that the taking of the exemplars violated none of petitioner’s constitutional rights.
First. The taking of the exemplars did not violate petitioner’s Fifth Amendment privilege against self-incrimination. The privilege reaches only compulsion of “an accused’s communications, whatever form they might take, and the compulsion of responses which are also communications, for example, compliance with a subpoena to produce one’s papers,” and not “compulsion which makes a suspect or accused the source of ‘real or physical evidence’, ; . .” Schmerber v. California, 384 U. S. 757, 763-764. One’s voice and handwriting are, of course, means of communication. It by no means follows, however, that every compulsion of an accused to use his voice or write compels a communication within the cover of the privilege. A mere handwriting exemplar, in contrast to the content of what is written, like the voice or body itself, is an identifying physical characteristic outside its protection. United States v. Wade, supra, at 222-223. No claim is made that the content of the exemplars was testimonial or communicative matter. Cf. Boyd v. United States, 116 U. S. 616.
Second. The taking of the exemplars was not a “critical” stage of the criminal proceedings entitling petitioner to the assistance of counsel. Putting aside the fact that the exemplars were taken before the indictment and appointment of counsel, there is minimal risk that the absence of counsel might derogate from his right to a fair trial. Cf. United States v. Wade, supra. If, for some reason, an unrepresentative exemplar is taken, this can be brought out and corrected through the adversary process at trial since the accused can make an unlimited number of additional exemplars for analysis and comparison by government and defense handwriting experts. Thus, “the accused has the opportunity for a meaningful confrontation of the [State’s] case at trial through the ordinary processes of cross-examination of the [State’s] expert [handwriting] witnesses and the presentation of the evidence of his own [handwriting] experts.” United States v. Wade, supra, at 227-228.
II.
Admission op Co-Dependant’s Statements.
Petitioner contends that he was denied due process of law by the admission during the guilt stage of the trial of his accomplice’s pretrial statements to the police which referred to petitioner 159 times in the course of reciting petitioner’s role in the robbery and murder. The statements were inadmissible hearsay as to petitioner, and were held on King’s aspect of this appeal to be improperly obtained from him and therefore to be inadmissible against him under California law. 63 Cal. 2d, at 699-701, 408 P. 2d, at 370-371.
Petitioner would have us reconsider Delli Paoli v. United States, 352 U. S. 232 (where the Court held that appropriate instructions to the jury would suffice to prevent prejudice to a defendant from the references to him in a co-defendant’s statement), at least as applied to a case, as here, where the co-defendant gained a reversal because of the improper admission of the statements. We have no occasion to pass upon this contention. The California Supreme Court has rejected the Delli Paoli rationale, and relying at least in part on the reasoning of the Delli Paoli dissent, regards cautionary instructions as inadequate to cure prejudice. People v. Aranda, 63 Cal. 2d 518, 407 P. 2d 265. The California court applied Aranda in this case but held that any error as to Gilbert in the admission of King’s statements was harmless. The harmless-error standard applied was that “there is no reasonable possibility that the error in admitting King’s statements and testimony might have contributed to Gilbert’s conviction,” a standard derived by the court from our decision in Fahy v. Connecticut, 375 U. S. 85. Fahy was the basis of our holding in Chapman v. California, 386 U. S. 18, and the standard applied by the California court satisfies the standard as defined in Chapman.
It may be that the California Supreme Court will review the application of its harmless-error standard to King’s statements if on the remand the State presses harmless error also in the introduction of the in-court and lineup identifications. However, this at best implies an ultimate application of Aranda and only confirms that petitioner’s argument for reconsideration of Delli Paoli need not be considered at this time.
III.
The Search-and-Seizure Claim.
The California Supreme Court rejected Gilbert’s challenge to the admission of certain photographs taken from his apartment pursuant to a warrantless search. The court justified the entry into the apartment under the circumstances on the basis of so-called “hot pursuit” and “exigent circumstances” exceptions to the warrant requirement. We granted certiorari to consider the important question of the extent to which such exceptions may permit warrantless searches without violation of the Fourth Amendment. A closer examination of the record than was possible when certiorari was granted reveals that the facts do not appear with sufficient clarity to enable us to decide that question. See Appendix to this opinion; compare Warden v. Hayden, 387 U. S. 294. We therefore vacate certiorari on this issue as improvidently granted. The Monrosa v. Carbon Black Export, Inc., 359 U. S. 180, 184.
IV.
The In-court and Lineup Identifications.
Since none of the petitioner’s other contentions warrants relief, the issue becomes what relief is required by application to this case of the principles today announced in United States v. Wade, supra.
Three eyewitnesses to the Alhambra crimes who identified Gilbert at the guilt stage of the trial had observed him at a lineup conducted without notice to his counsel in a Los Angeles auditorium 16 days after his indictment and after appointment of counsel. The manager of the apartment house in which incriminating evidence was found, and in which Gilbert allegedly resided, identified Gilbert in the courtroom and also testified, in substance, to her prior lineup identification on examination by the State. Eight witnesses who identified him in the courtroom at the penalty stage were not eyewitnesses to the Alhambra crimes but to other robberies allegedly committed by him. In addition to their in-court identifications, these witnesses also testified that they identified Gilbert at the same lineup.
The lineup was on a stage behind bright lights which prevented those in the line from seeing the audience. Upwards of 100 persons were in the audience, each an eyewitness to one of the several robberies charged to Gilbert. The record is otherwise virtually silent as to what occurred at the lineup.
At the guilt stage, after the first witness, a cashier of the savings and loan association, identified Gilbert in the courtroom, defense counsel moved, out of the presence of the jury, to strike her testimony on the ground that she identified Gilbert at the pretrial lineup conducted in the absence of counsel in violation of the Sixth Amendment made applicable to the States by the Fourteenth Amendment. Gideon v. Wainwright, 372 U. S. 335. He requested a hearing outside the presence of the jury to present evidence supporting his claim that her in-court identification was, and others to be elicited by the State from other eyewitnesses would be, “predicated at least in large part upon their identification or purported identification of Mr. Gilbert at the showup ....” The trial judge denied the motion as premature. Defense counsel then elicited the fact of the cashier’s lineup identification on cross-examination and again moved to strike her identification testimony. Without passing on the merits of the Sixth Amendment claim, the trial judge denied the motion on the ground that, assuming a violation, it would not in any event entitle Gilbert to suppression of the in-court identification. Defense counsel thereafter elicited the fact of lineup identifications from two other eyewitnesses who on direct examination identified Gilbert in the courtroom. Defense counsel unsuccessfully objected at the penalty stage, to the testimony of the eight witnesses to the other robberies that they identified Gilbert at the lineup.
The admission of the in-court identifications without first determining that they were not tainted by the illegal lineup but were of independent origin was constitutional error. United States v. Wade, supra. We there held that a post-indictment pretrial lineup at which the accused is exhibited to identifying witnesses is a critical stage of the criminal prosecution; that police conduct of such a lineup without notice to and in the absence of his counsel denies the accused his Sixth Amendment right to counsel and calls in question the admissibility at trial of the in-court identifications of the accused by witnesses who attended the lineup. However, as in Wdde, the record does not permit an informed judgment whether the in-court identifications at the two stages of the trial had an independent source. Gilbert is therefore entitled only to a vacation of his conviction pending the holding of such proceedings as the California Supreme Court may deem appropriate to afford the State the opportunity to establish that the in-court identifications had an independent source, or that their introduction in evidence was in any event harmless error.
Quite different considerations are involved as to the admission of the testimony of the manager of the apartment house at the guilt phase and of the eight witnesses at the penalty stage that they identified Gilbert at the lineup. That testimony is the direct result of the illegal lineup “come at by exploitation of [the primary] illegality.” Wong Sun v. United States, 371 U. S. 471, 488. The State is therefore not entitled to an opportunity to show that that testimony had an independent source. Only a per se exclusionary rule as to such testimony can be an effective sanction to assure that law enforcement authorities will respect the accused’s constitutional right to the presence of his counsel at the critical lineup. In the absence of legislative regulations adequate to avoid the hazards to a fair trial which inhere in lineups as presently conducted, the desirability of deterring the constitutionally objectionable practice must prevail over the undesirability of excluding relevant evidence. Cf. Mapp v. Ohio, 367 U. S. 643. That conclusion is buttressed by the consideration that the witness’ testimony of his lineup identification will enhance the impact of his in-court identification on the jury and seriously aggravate whatever derogation exists of the accused's right to a fair trial. Therefore, unless the California Supreme Court is “able to declare a belief that it was harmless beyond a reasonable doubt,” Chapman v. California, 386 U. S. 18, 24, Gilbert will be entitled on remand to a new trial or, if no prejudicial error is found on the guilt stage but only in the penalty stage, to whatever relief California law affords where the penalty stage must be set aside.
The judgment of the California Supreme Court and the conviction are vacated, and the case is remanded to that court for further proceedings not inconsistent with this opinion.
It is so ordered.
The Chief Justice joins this opinion except for Part III, from which he dissents for the reasons expressed in the opinion of Mr. Justice Douglas.
APPENDIX TO OPINION OF THE COURT.
Photographs of Gilbert introduced at the guilt stage of the trial had been viewed by eyewitnesses within hours after the robbery and murder. Officers had entered his apartment without a warrant and found them in an envelope on the top of a bedroom dresser. The envelope was of the kind customarily used in delivering developed prints, with the words “Marlboro Photo Studio” imprinted on it. The officers entered the apartment because of information given by an accomplice which led them to believe that one of the suspects might be inside the apartment. Assuming that the warrant-less entry into the apartment was justified by the need immediately to search for the suspect, the issue remains whether the subsequent search was reasonably supported by those same exigent circumstances. If the envelope were come upon in the course of a search for the suspect, the answer might be different from that where it is come upon, even though in plain view, in the course of a general, indiscriminate search of closets, dressers, etc., after it is known that the occupant is absent. Still different considerations may be presented where officers, pursuing the suspect, find that he is absent from the apartment but conduct a limited search for suspicious objects in plain view which might aid in the pursuit. The problem with the record in the present case is that it could reasonably support any of these factual conclusions upon which our constitutional analysis should rest, and the trial court made no findings on the scope of search. The California Supreme Court, which had no more substantial basis upon which to resolve the conflict than this Court, stated that the photos were come upon “while the officers were looking through the apartment for their suspect . . . .” As will appear, a contrary conclusion is equally reasonable.
(1) Agent Schlatter testified that immediately upon entering the apartment which he put at “approximately 1:05,” the officers made a quick search for the occupant, which took at most a minute, and that the continued presence of the officers became “a matter of a stake-out under the assumption that the person or persons involved would come back.” He testified that the officer who found the photographs, Agent Crowley, had entered the apartment with him. Agent Schlatter’s testimony might support the California Supreme Court’s view of the scope of search; (2) Agent Crowley testified that he arrived within five minutes after Agent Schlatter, “around 1:30, give or take a few minutes either way,” that the apartment had already been searched for the suspects, and that he was instructed “to look through the apartment for anything we could find that we could use to identify or continue the pursuit of this person without conducting a detailed search.” Crowley's further testimony was that the search, pursuant to which the photos were found, was limited in this manner, and that he merely inspected objects in plain sight which would aid in identification. He stated that a detailed search for guns and money was not conducted until after a warrant had issued over three hours later. (3) Agent Townsend said he arrived at the apartment “sometime between perhaps 1:30 and 2:00,” and that “well within an hour” he, Agent Crowley, another agent and a local officer conducted a detailed search of the bedroom. He stated that they “looked through the bedroom closet and dresser and I think . . . the headstand.” A substantial sum of money was found in the dresser. Townsend could not “specifically say” whether Crowley was in the bedroom at the time the money was found. This testimony might support a finding that the officers were engaged in a general search of the bedroom at the time the photos were found.
The testimony of the agents concerning their time of arrival in the apartment is not inconsistent with any of the three possible conclusions as to the scope of search. Taking Townsend’s testimony together with Crowley’s, it can be concluded that the two arrived at about the same time. Agent Schlatter’s testimony that Crowley arrived with him at 1:05, however, supports a conclusion that Crowley had begun his activities before Townsend arrived. Then there is the testimony of Agent Kiel, who did not enter the apartment, that he obtained the photos while talking with the landlady “approximately 1:25 to 1:30,” about the same time that both Crowley and Townsend testified they arrived. In sum, the testimony concerning the timing of the events surrounding the search is both approximate and itself contradictory.
The California Supreme Court also held that "... the erroneous admission of King’s statements at the trial on the issue of guilt was not prejudicial on the question of Gilbert’s penalty,” again citing Fahy, 63 Cal. 2d, at 702, 408 P. 2d, at 372.
The record in Gilbert v. United States, 366 F. 2d 923, involving the federal prosecutions of Gilbert, apparently contains many more details of what occurred at the lineup. The opinion of the Court of Appeals for the Ninth Circuit states, 366 F. 2d, at 935:
“The lineup occurred on March 26, 1964, after Gilbert had been indicted and had obtained counsel. It was held in an auditorium used for that purpose by the Los Angeles police. Some ten to thirteen prisoners were placed on a lighted stage. The witnesses were assembled in a darkened portion of the room, facing the stage and separated from it by a screen. They could see the prisoners but could not be seen by them. State and federal officers were also present and one of them acted as 'moderator1 of the proceedings.
“Each man in the lineup was identified by number, but not b}r name. Each man was required to step forward into a marked circle, to turn, presenting both profiles as well as a face and back view, to walk, to put on or take off certain articles of clothing. When a man’s number was called and he was directed to step into the circle, he was asked certain questions: where he was picked up, whether he owned a car, whether, when arrested, he was armed, where he lived. Each was also asked to repeat certain phrases, both in a loud and in a soft voice, phrases that witnesses to the crimes had heard the robbers use: 'Freeze, this is a stickup; this is a holdup; empty your cash drawer; this is a heist; don’t anybody move.’
“Either while the men were on the stage, or after they were taken from it, it is not clear which, the assembled witnesses were asked if there were any that they would like to see again, and told that if they had doubts, now was the time to resolve them. Several gave the numbers of men they wanted to see, including Gilbert’s. While the other prisoners were no longer present, Gilbert and 2 or 3 others were again put through a similar procedure. Some of the witnesses asked that a particular prisoner say a particular phrase, or walk a particular way. After the lineup, the witnesses talked to each other; it is not clear that they did so during the lineup. They did, however, in each other’s presence, call out the numbers of men they could identify.”
There is a split among the States concerning the admissibility of prior extrajudicial identifications, as independent evidence of identity, both by the witness and third parties present at the prior identification. See 71 ALR 2d 449. It has been held that the prior identification is hearsay, and, when admitted through the testimony of the identifier, is merely a prior consistent statement. The recent trend, however, is to admit the prior identification under the exception that admits as substantive evidence a prior communication by a witness who is available for cross-examination at trial. See 5 ALR 2d Later Case Service 1225-1228. That is the California rule. In People v. Gould, 54 Cal. 2d 621, 626, 354 P. 2d 865, 867, the Court said:
“Evidence of an extrajudicial identification is admissible, not only to corroborate an identification made at the trial (People v. Slobodion, 31 Cal. 2d 555, 560 [191 P. 2d 1]), but as independent evidence of identity. Unlike other testimony that cannot be corroborated by proof of prior consistent statements unless it is first impeached . . . evidence of an extrajudicial identification is admitted regardless of whether the testimonial identification is impeached, because the earlier identification has greater probative value than an identification made in the courtroom after the suggestions of others and the circumstances of the trial may have intervened to create a fancied recognition in the witness’ mind. . . . The failure of the witness to repeat the extrajudicial identification in court does not destroy its probative value, for such failure may be explained by loss of memory or other circumstances. The extrajudicial identification tends to connect the defendant with the crime, and the principal danger of admitting hearsay evidence is not present since the witness is available at the trial for cross-examination.” New York deals with the subject in a statute. See N. Y. Code Crim. Proc. § 393-b.