In April 2006, a stray 9-millimeter bullet killed a 2-year-old child after a street fight in the Bronx. Eyewitnesses described the shooter as wearing a blue shirt or sweater. Police officers determined Ronnell Gilliam was involved and that Nicholas Morris had been at the scene. A search of Morris’ apartment revealed a 9-millimeter cartridge and three .357-caliber bullets. Gilliam initially identified Morris as the shooter, but he subsequently said that Darrell Hemphill, Gilliam’s cousin, was the shooter. Not crediting Gilliam’s recantation, the State charged Morris with the child’s murder and possession of a 9-millimeter handgun. In a subsequent plea deal, the State agreed to dismiss the murder charges against Morris if he pleaded guilty to a new charge of possession of a .357 revolver, a weapon that had not killed the victim. Years later, the State indicted Hemphill for the child’s murder after learning that Hemphill’s DNA matched a blue sweater found in Morris’ apartment shortly after the murder. At his trial, Hemphill elicited undisputed testimony from a prosecution witness that police had recovered 9-millimeter ammunition from Morris’ apartment, thus pointing to Morris as the culprit. Morris was not available to testify at Hemphill’s trial because he was outside the United States. Relying on People v. Reid, 19 N. Y. 3d 382, 388, 971 N. E. 2d 353, 357, and over the objection of Hemphill’s counsel, the trial court allowed the State to introduce parts of the transcript of Morris’ plea allocution to the .357 gun possession charge as evidence to rebut Hemphill’s theory that Morris committed the murder. The court reasoned that although Morris’ out-of-court statements had not been subjected to cross-examination, Hemphill’s arguments and evidence had “opened the door” and admission of the statements was reasonably necessary to correct the misleading impression Hemphill had created. The State, in its closing argument, cited Morris’ plea allocution and emphasized that possession of a .357 revolver, not murder, was the crime Morris committed. The jury found Hemphill guilty. Both the New York Appellate Division and the Court of Appeals affirmed Hemphill’s conviction.

Held: The trial court’s admission of the transcript of Morris’ plea allocution over Hemphill’s objection violated Hemphill’s Sixth Amendment right to confront the witnesses against him. Pp. 6–15.

 (a) The State’s threshold argument—that Hemphill’s failure to present his claim adequately to the state courts should prevent the Court from deciding his federal-law challenge to the state-court decision—is rejected. Hemphill satisfied the presentation requirement in state court. See Street v. New York, 394 U. S. 576, 584. At every level of his proceedings in state court, Hemphill argued that the admission of Morris’ plea allocution violated his Sixth Amendment right to confrontation as interpreted by this Court. And “[o]nce a federal claim is properly presented, a party can make any argument in support of that claim.” Yee v. Escondido, 503 U. S. 519, 534. Pp. 6–8.

 (b) The Confrontation Clause of the Sixth Amendment provides a criminal defendant the bedrock right “to be confronted with the witnesses against him.” In Crawford v. Washington, 541 U. S. 36, the Court examined the history of the confrontation right at common law and concluded that “the principal evil at which the Confrontation Clause was directed was the civil-law mode of criminal procedure,” which allowed the “use of ex parte examinations as evidence against the accused.” Id., at 50. The Crawford Court reasoned that because “the Sixth Amendment does not suggest any open-ended exceptions from the confrontation requirement to be developed by the courts,” the confrontation guarantee was “most naturally read” to admit “only those exceptions established at the time of the founding.” Id., at 54; see also Giles v. California, 554 U. S. 353, 377. Because “the Framers would not have allowed admission of testimonial statements of a witness who did not appear at trial unless he was unavailable to testify, and the defendant had had a prior opportunity for cross-examination,” the Court rejected its previous “reliability approach” to the Sixth Amendment’s confrontation right described in Ohio v. Roberts, 448 U. S. 56, 66, which had permitted the admission of statements of an unavailable witness so long as those statements had “adequate indicia of reliability.” Pp. 8–9.

 (c) The Court rejects the State’s contention that the “opening the door” rule incorporated in People v. Reid and applied here is not a Confrontation Clause exception at all but merely a “procedural rule” limiting only the manner of asserting the confrontation right, not its substantive scope. While the Court’s precedents do recognize that the Sixth Amendment leaves States with flexibility to adopt reasonable procedural rules that bear on the exercise of a defendant’s confrontation right, see, e.g., Melendez-Diaz v. Massachusetts, 557 U. S. 305, 327, the door-opening principle discussed in Reid is not in the same class of procedural rules. Reid’s door-opening principle is a substantive principle of evidence that dictates what material is relevant and admissible in a case. The State would have trial judges weigh the reliability or credibility of testimonial hearsay evidence, but that approach would negate Crawford’s emphatic rejection of the reliability-based approach to the Confrontation Clause guarantee. Here, it was not for the trial judge to determine whether Hemphill’s theory that Morris was the shooter was unreliable, incredible, or otherwise misleading in light of the State’s proffered, unconfronted plea evidence, nor whether this evidence was reasonably necessary to correct that misleading impression. Pp. 9–11.

 (d) The Court also rejects the State’s insistence that the Reid rule is necessary to safeguard the truth-finding function of courts because it prevents the selective and misleading introduction of evidence. The Court has not allowed such considerations to override the rights the Constitution confers to criminal defendants. And none of the cases the State relies upon for support—Kansas v. Ventris, 556 U. S. 586; Harris v. New York, 401 U. S. 222; Walder v. United States, 347 U. S. 62—involved exceptions to constitutional requirements. Pp. 11–13.

 (e) The State’s concern that a reversal will leave prosecutors without recourse to protect against abuses of the confrontation right is overstated. “[W]ell-established rules” of evidence “permit trial judges to exclude evidence if its probative value is outweighed by certain other factors such as unfair prejudice, confusion of the issues, or potential to mislead the jury.” Holmes v. South Carolina, 547 U. S. 319, 326. Finally, the rule of completeness does not apply here, as Morris’ plea allocution was not part of any statement that Hemphill introduced. The Court does not address whether and under what circumstances that rule might allow the admission of testimonial hearsay against a criminal defendant. Pp. 13–14.

35 N. Y. 3d 1035, 150 N. E. 3d 356, reversed and remanded.

 Sotomayor, J., delivered the opinion of the Court, in which Roberts, C. J., and Breyer, Alito, Kagan, Gorsuch, Kavanaugh, and Barrett, JJ., joined. Alito, J., filed a concurring opinion, in which Kavanaugh, J., joined. Thomas, J., filed a dissenting opinion.