Arthur Nathaniel Aiken appeals the denial of his petition for writ of habeas corpus. He was convicted by a jury in 1965 in a Washington State court on three counts of first degree murder. Originally sentenced to death, Aiken is now serving three consecutive life terms. He argues, among other things, that the interrogating officers violated his right to counsel, and that his confessions were involuntary.

BACKGROUND

In March and April 1965, three service station attendants were robbed and murdered in the Seattle area. Antonio Wheat, appellant’s co-defendant, was arrested on April 24, 1965, the day of the third homicide. His statements to police implicated Aiken, who was arrested at 4:19 p.m. the next day, in Blaine, Washington. Aiken was taken to the County-City Building, in Seattle, at approximately 12:15 a.m., the morning of April 26, 1965. En route, the officers informed Aiken that he was being held on a charge of homicide and robbery, and advised him of his rights. At approximately 12:20 a.m., Officers Chase and Mullen began to question Aiken regarding one of the homicides. Without the knowledge of the interrogating officers or Aiken, virtually all of the initial interrogation session was tape-recorded.

*882 After Aiken denied any and all knowledge of the crimes, the officers told him (truthfully) that his co-defendant, Wheat, had given a statement blaming the murders on Aiken. Aiken was permitted to read Wheat’s statement regarding one of the homicides, after which the following colloquy ensued:

(Emphasis supplied.) Aiken continued to insist that the charges were “counterfeit.” At 1:00 a.m., Chief Detective Nault entered the interview room and corroborated the fact that Wheat had given the statement Aiken had read. Nault offered Aiken a chance to tell his side of the story. Aiken requested the opportunity to confront Wheat. When Wheat was brought into the room he confirmed that he had made the statement. Aiken reiterated that it was a lie and said that he wanted to give his version of events.

Aiken proceeded to make and sign three statements admitting to participation in each of the three homicides, maintaining throughout that Wheat was the one who actually fired the shots. Prior to making each statement, Aiken was admonished by the interrogating officers that he had the right to remain silent, the right to an attorney and that anything he said could be used as evidence against him. In each instance, Aiken stated that he understood his rights.

Both Aiken and Wheat were convicted on three counts of first degree murder and sentenced by the court to death. The Supreme Court of the State of Washington, on direct appeal, found that the interrogation tape “may reveal at least two occasions when said defendant Aiken may have requested the assistance of counsel.” The Court remanded the cause to the trial court for the purpose of conducting a supplemental hearing on the voluntariness and admissibility of Aiken’s statements.

At the supplemental hearing, held in May 1967, the interrogation tape was played repeatedly on the original machine and on a new Tandberg 923-E tape recorder. Officers Mullen and Chase testified that they did not hear Aiken request the assistance of an attorney or express a wish to terminate the interrogation. The court stated that it heard “what appears to be a request by the defendant Aiken for an attorney on possibly two occasions,” but that nevertheless:

The court concluded that Aiken had waived his right to counsel and that his statements *883 had been given freely and voluntarily. By a 5-4 vote, the Washington Supreme Court affirmed the judgments and sentences. State v. Aiken, 72 Wash.2d 306 , 434 P.2d 10 (1967). Several appeals followed. 1

On September 5, 1985, the district court denied Aiken’s habeas corpus petition, which is now before us on appeal. 2

DISCUSSION

In his habeas petition, Aiken presents new evidence that is material to the issue of whether the interrogating officers heard and ignored Aiken’s requests for counsel and for the interrogation to cease. This evidence consists of decibel-level studies by an expert, Dr. Shipp, who examined the original tape recordings using modern sound equipment.

The “decibel-level” evidence was, of course, not available at any stage of the proceedings in state court. Aiken’s presentation of new evidence at this juncture raises the question of whether he has fully exhausted his state remedies. Although the state Attorney General appears to have “conceded” that Aiken exhausted his state remedies, see Magistrate’s Report at 9, we may examine the exhaustion question sua sponte. Granberry v. Greer, — U.S. —, 107 S.Ct. 1671, 1675 , 95 L.Ed.2d 119 (1987); Batchelor v. Cupp, 693 F.2d 859, 862-63 (9th Cir.1982) (rejecting state’s position that petitioner had exhausted state remedies); Campbell v. Crist, 647 F.2d 956, 957 (9th Cir.1981).

In Dispensa v. Lynaugh, 826 F.2d 375 (5th Cir.1987), the habeas petition presented new evidence from a psychology expert regarding the possible inaccuracy of the identification procedure used to convict the defendant. The court held that this new evidence should be presented first to state court:

Dispensa, 826 F.2d at 377 (quoting Brown v. Estelle, 701 F.2d 494, 495 (5th Cir.1983)).

In the instant case, Aiken brought his federal habeas petition without having petitioned the state court for habeas relief. However, Dr. Shipp’s affidavit substantially improves the evidentiary basis for Aiken’s right-to-eounsel and voluntariness arguments, thereby presenting the very type of evidence which the state should consider in the first instance. See Granberry v. *884 Greer, — U.S. —, 107 S.Ct. at 1675 , 95 L.Ed.2d 119 ; Dispensa, 826 F.2d at 377 . 3

CONCLUSION

We VACATE the district court’s decision and DISMISS the habeas petition, without prejudice, for failure to exhaust state remedies.

. The judgments were vacated by the United States Supreme Court which remanded for reconsideration in light of its decisions regarding death-qualified juries and joint trials of co-defendants. Wheat v. Washington, 392 U.S. 652 , 88 S.Ct. 2302 , 20 L.Ed.2d 1357 (1968). On remand, the Supreme Court of Washington reaffirmed the convictions. State v. Aiken, 75 Wash.2d 421 , 452 P.2d 232 (1969). The Supreme Court again reversed the judgment, insofar as it imposed the death sentence, and remanded the case for resentencing. Aiken v. Washington, 403 U.S. 946 , 91 S.Ct. 2283 , 29 L.Ed.2d 856 (1971). The Washington Supreme Court remanded to the trial court which sentenced Aiken to three consecutive life terms.

. Aiken filed a pro se habeas petition in July 1979 in the District Court for the Eastern District of Washington. The case was transferred to the Western District where it was dismissed as untimely under Rule 9(a) of the Rules Governing Section 2254 cases, 28 U.S.C. foil. § 2254. On appeal we reversed and remanded for findings on the issue whether the state had suffered prejudice within the meaning of Rule 9(a). Aiken, with the assistance of counsel, filed an amended petition which the district court dismissed on September 2, 1981. This court again vacated the dismissal and remanded. Aiken v. Spalding, 684 F.2d 632 (9th Cir.1982), cert. denied, 460 U.S. 1093 , 103 S.Ct. 1795 , 76 L.Ed.2d 361 (1983).

On remand, the United States Magistrate heard oral argument, and recommended that Aiken’s petition be denied based on its findings that (1) there was "fair support in the record” for the conclusion by the trial court that the interrogating officers did not hear Aiken’s request to consult with an attorney; (2) under the totality of the circumstances, Aiken’s confessions were voluntary; (3) the trial judge did not arbitrarily deny defense counsel access to the interrogation tapes; and (4) Aiken did not establish that he was denied a fair trial or impartial jury due to pretrial publicity. The magistrate’s recommendations were adopted by the district court.

. Our holding is consistent with Vasquez v. Hillery, 474 U.S. 254, 258-60 , 106 S.Ct. 617, 620-22 , 88 L.Ed.2d 598 (1986). There, the Supreme Court held that a habeas petitioner had not circumvented his obligation to exhaust state remedies by presenting expert statistical analysis to support his claim that the indicting grand jury systematically excluded blacks. The Court noted that the evidence was not "new,” because it "added nothing to the case that this court has not considered intrinsic to the consideration of any grand jury discrimination claim.” Id. at 259 , 106 S.Ct. at 621 . In addition, the Court relied on the fact that the district court had requested the evidence pursuant to its power to expand the existing evidentiary record under Rule 7(b), 28 U.S.C. foil. § 2254. Here, by contrast, the new evidence was presented by the habeas petitioner on his own initiative, and the evidence places his claim in a significantly different and stronger evidentiary posture than it had when presented in state court. For instance, Dr. Shipp’s evidence controverts the live testimony given by officers Mullen and Chase at the 1967 hearing. Accordingly, we find Vasquez to be distinguishable and Granbeny and Dispen-sa controlling.