In Bruton v. United States (1968) 391 U.S. 123, the United States Supreme Court addressed the issue of using one defendant's out-of-court statements, there a confession, at a joint trial charging two defendants with armed postal robbery. Part of one defendant's out-of-court statements implicated the second defendant in the crime. The Supreme Court ruled that when a defendant makes an out-of-court statement implicating a codefendant, and the former does not testify at trial, admitting evidence of the first defendant's out-of-court statement implicating the codefendant at a joint trial violates the codefendant's Sixth Amendment right of confrontation, and it is not enough for a trial court to give a cautionary instruction to the jurors that they are not to consider the first defendant's out-of-court statement in determining the second defendant's guilt. (Id. at pp. 135-137.) As the Supreme Court summarized: "Despite the concededly clear instructions to the jury to disregard Evans' inadmissible hearsay evidence inculpating petitioner, in the context of a joint trial we cannot accept limiting instructions as an adequate substitute for petitioner's constitutional right of cross-examination." (Id. at p. 137.) Accordingly, since Bruton, the rule for joint trials ordinarily followed has been to exclude evidence of one defendant's out-of-court statement implicating a codefendant unless the trial court redacts the part implicating the codefendant. (See, e.g., People v. Fletcher (1996) 13 Cal.4th 451, 455.) When evidence of one defendant's out-of-court statement is erroneously admitted against a codefendant under Bruton, the error is examined for prejudice under Chapman v. California (1967) 386 U.S. 18, 24, because the error involves the constitutional right of confrontation. (People v. Burney (2009) 47 Cal.4th 203, 232.) In short, Bruton error is "not reversible per se." (Ibid.) Instead, a reviewing court must determine whether the improperly admitted Bruton evidence prejudiced the objecting defendant; the error may be found harmless when the remaining, properly admitted evidence against the defendant is overwhelming and the evidence of the incriminating out-of-court statement is largely cumulative of other direct evidence. (Ibid.) Stated in other words: "To find Bruton error harmless we must find beyond a reasonable doubt that it did not contribute to the verdict, that it was unimportant in relation to everything else the jury considered on the issue in question." (People v. Song (2004) 124 Cal.App.4th 973, 984, citing Yates v. Evatt (1991) 500 U.S. 391, 403.) Nearly 40 years after Bruton, the United States Supreme Court in Crawford v. Washington (2004) 541 U.S. 36 (Crawford) clarified that a defendant's right of confrontation only applies to an out-of-court statement that is "testimonial" in nature. (Id. at pp. 56-68.) "Where nontestimonial hearsay is at issue," the Sixth Amendment affords the states "flexibility in their development of hearsay law," and "exempts such statements from confrontation clause scrutiny altogether." (Id. at p. 68.) The Supreme Court expressly declined to define when an out-of-court statement should be considered "testimonial" for purposes of confrontation clause analysis: "We leave for another day any effort to spell out a comprehensive definition of 'testimonial.' Whatever else the term covers, it applies at a minimum to prior testimony at a preliminary hearing, before a grand jury, or at a former trial; and to police interrogations." (Id. at p. 69.) In two subsequent companion cases, Davis v. Washington (2006) 547 U.S. 813, and Hammon v. Indiana (2006) 547 U.S. 813, the United States Supreme Court began trying to clarify when an out-of-court statement will be considered "testimonial" for purposes of the confrontation clause. In Davis, the court reiterated that only a statement that is testimonial in nature "cause the declarant to be a 'witness' within the meaning of the Confrontation Clause. . . . It is the testimonial character of the statement that separates it from other hearsay that, while subject to traditional limitations upon hearsay evidence, is not subject to the Confrontation Clause." (Id. at p. 821.) In that vein, the Court explained that "statements are nontestimonial when made in the course of police interrogation under circumstances objectively indicating that the primary purpose of the interrogation is to enable police assistance to meet an ongoing emergency. They are testimonial when the circumstances objectively indicate that there is no such ongoing emergency, and that the primary purpose of the interrogation is to establish or prove past events potentially relevant to later criminal prosecution." (Id. at pp. 814-815.) In Hammon, police responded to a domestic disturbance radio call and found the defendant's wife alone on the front porch. She seemed "'somewhat frightened'" but said nothing was the matter. There were signs of recent violence at the residence. Defendant, who was in the kitchen, said that he and his wife had had an argument but "'"everything was fine now."'" In responses to questions by an officer, the wife related that defendant had assaulted her, breaking household objects and throwing her on the floor. (Hammon, supra, 547 U.S. at pp. 819-820.) At that time, there was neither an ongoing emergency nor an immediate threat to the wife's person. The officer was not seeking to find out what was happening, but what had happened. While the interrogation was not as formal as the one in Crawford, it was formal enough: It was carried on in a separate room from the room defendant was in, and the officer was asking the wife questions for use in an "investigation." (Hammon, supra, at pp. 829-830.)