OPINION
STAFFORD, District Judge.
Petitioner, Vincent L. Calvert (“Calvert”), appeals the denial of his petition for writ of habeas corpus by a person in state custody. We reverse.
I. THE EVIDENCE
In February of 1996, the grand jury of Guernsey County, Ohio, returned an indictment charging Calvert and Erwin Mallory (“Mallory”) with one count of aggravated robbery and one count of aggravated murder with a death penalty specification. Although charged in the same indictment with the same offenses, Calvert and Mallory were tried separately. Calvert went to trial first.
At Calvert’s trial, the prosecutor introduced a statement given by Calvert to police officers after his arrest. According to Calvert, on the afternoon of February 4, 1996, he spent three or four hours playing cards and drinking whiskey with Robert Bennett (“Bennett”) in Bennett’s apartment. When he left Bennett’s apartment at four or five o’clock in the afternoon, Calvert first went to the apartment of Paul Bates, from whom he borrowed some money, then went to the apartment of an acquaintance, Cindy Chalfant (“Chalfant”), who lived in the apartment next to Bennett’s. Mallory soon after knocked on Chalfant’s door and asked Calvert to go next door with him to see Bennett, who— Mallory said — had ripped Mallory off the previous night for one hundred dollars. When Bennett, a white man, saw Mallory at his door, he immediately began yelling at Mallory, using a racial epithet and telling him to get out. All three men were intoxicated.
[826]*826Calvert told police officers that, not thirty seconds after Mallory and Calvert entered Bennett’s apartment, Mallory pulled a hatchet from under his field jacket and started hitting Bennett on the back of the head. After several hits, Mallory stopped the beating and even helped Bennett into a chair at the kitchen table. He began the beating again, however, this time with a stick, when he heard Bennett ask Calvert to help him get Mallory out of his house. When the stick broke, Mallory picked up a butcher knife and — approaching Bennett from behind — slashed Bennett across the throat. Calvert, who was sitting at the table facing Bennett when blood started flying, got up from his chair, told Mallory he was crazy, and ran from the scene, leaving Mallory and Bennett — still alive at the time — in the apartment.
Calvert explained that, after leaving Bennett’s apartment, he took a cab to a bar in Byesville, Ohio. He stayed at the bar until closing, at which time friends took him to his home, which was also in Byesville. The next morning, he took a cab to Chalfant’s apartment where police officers soon after found him still dressed in the blood-spattered clothes he was wearing the evening before. Calvert told the officers that he neither killed Bennett nor knew anything about Mallory’s plan to kill him. Calvert was placed under arrest and taken to the police department where he gave the statement that was later heard by the jury at trial.
The prosecutor called Mallory as a witness, but Mallory asserted his Fifth Amendment privilege against self-incrimination and refused to testify. Over defense counsel’s objection, the trial court then admitted a tape-recorded confession given by Mallory to the police after his arrest. In that confession, Mallory described a different version of the events that resulted in Bennett’s death.
Mallory admitted that he and Bennett argued on February 3, 1996, the day before the murder, about some money Mallory claimed he had won from Bennett in a card game. A neighbor broke up the argument, telling Mallory — among other things — to put down the ax he was using to threaten Bennett. Mallory did not explain to the officers why he had taken an ax to Bennett’s apartment.
Mallory told the officers that Bennett invited both Mallory and Calvert to play cards with him the very next evening, February 4, 1996. After playing cards for approximately fifteen minutes, Mallory and Calvert left Bennett to go to Mallory’s apartment where they armed themselves with knives and a hammer for the purpose of killing Bennett. The two men soon after returned to Bennett’s apartment, where — according to Mallory- — -they both attacked Bennett, Calvert using the hammer and a paring-type knife, Mallory using a butcher knife and Bennett’s walking stick. Mallory said that after he and Calvert had beaten and stabbed Bennett multiple times, Calvert slashed Bennett’s throat. The two then left Bennett’s apartment.
While Calvert returned to Chalfant’s apartment to call a cab, Mallory returned to his own apartment to change clothes. Mallory admitted that, while he was there, he disposed of the murder weapons. He threw the hammer out a window in his apartment and he dropped the knives in the storm sewer in front of his apartment building. Mallory explained that a third knife, which was found by police officers inside Mallory’s building on the ground floor, was not used on Bennett.
Responding to Calvert’s call, a Round the Clock Cab Company cabdriver picked up both Calvert and Mallory, taking them to a bar in Byesville. Mallory said that he left the bar about thirty minutes later to [827]*827go back to his apartment. He was arrested the next day at home.
Bennett’s grandson, Brian Bennett, testified that, when he visited his grandfather early on the evening of February 4, 1996, his grandfather was upset not only about having lost some money but also about Mallory’s having threatened him with a butcher knife. The grandson said that he had known Mallory for three or four months before his grandfather’s death but had never met or seen Calvert.
Dr. Patrick Fardal testified that Bennett died as a result of multiple stab wounds to his trunk, chest and abdomen. He did not die from trauma to the head.
II. THE PROCEEDINGS
The jury found Calvert guilty as charged. The trial court followed the jury’s recommendation and sentenced Calvert to life imprisonment, with parole eligibility after thirty full years, for the aggravated murder. The judge sentenced Calvert to a consecutive term of ten to twenty-five years in prison for the aggravated robbery.
Calvert appealed his conviction to the Guernsey County Court of Appeals, arguing, among other things, that the trial court • erred by allowing Mallory’s tape-recorded statement into evidence, contrary to the Confrontation Clause of the Sixth Amendment to the United States Constitution. The Guernsey County Court of Appeals affirmed Calvert’s conviction, finding that Mallory’s statement was properly admitted as a statement against the declar-ant’s interest under Rule 804(b)(3) of the Ohio Rules of Evidence. The appellate court also found that Mallory’s statement “was collaborated [sic] by other evidence and witnesses” and was, therefore, trustworthy. Calvert’s appeal for discretionary review in the Ohio Supreme Court was dismissed on April 1, 1998, as not involving any substantial constitutional question.
On February 19, 1999, Calvert filed a petition for writ of habeas corpus under 28 U.S.C. § 2254 in federal district court. He again raised the Confrontation Clause issue. The district court found that the trial court’s admission of Mallory’s statement was error, constituting a violation of Calvert’s right to confront witnesses. Calvert was nonetheless denied relief because the district court found the error to be harmless. Calvert filed a timely notice of appeal, and the district court granted leave to proceed informa pauperis and a certificate of appealability on the Confrontation Clause issue.
III. STANDARD OF REVIEW
We review a district court’s legal conclusions in a habeas proceeding de novo and its factual findings for clear error. Lucas v. O’Dea, 179 F.3d 412, 416 (6th Cir.1999). Because Calvert’s habeas petition was filed after April 24, 1996, our review is governed by the Antiterrorism and Effective Death Penalty Act of 1996 (“AEDP1A”), 1996, Pub.L. No. 104-132, 110 Stat. 1214 (1996). As amended, AED-PA provides, in relevant part, that a federal court may not grant a petition for writ of habeas corpus unless the state court adjudication of the claim “resulted in a decision that was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States.” 28 U.S.C. § 2254(d).
In Williams v. Taylor, 529 U.S. 362, 120 S.Ct. 1495, 146 L.Ed.2d 389 (2000), the Supreme Court explained that a state court acts “contrary to” clearly established Supreme Court precedent if it “arrives at a conclusion opposite to that reached by this Court on a question of law” or if it “decides a case differently than this Court has on a set of materially indistinguishable facts.” Williams, 529 [828]*828U.S. at 413, 120 S.Ct. 1495 (Justice O’Con-nor’s Part II majority opinion). The Court also explained that a state court’s decision involves an “unreasonable application” of clearly established federal law if it either (1) correctly identifies the governing legal principle from the Supreme Court’s decisions but then unreasonably applies that principle to the facts of the prisoner’s case, or (2) unreasonably extends, or unreasonably declines to extend, a clearly established legal principle to a new context. Notably, an “unreasonable” application is an “objectively unreasonable” application. Williams, 529 U.S. at 412, 120 S.Ct. 1495.
IV. PETITIONER’S SIXTH AMENDMENT CLAIM
A.
The Sixth Amendment’s Confrontation Clause provides that “[i]n all criminal prosecutions, the accused shall enjoy the right ... to be confronted with the witnesses against him.” U.S. Const, amend. VI. The Supreme Court has long held that a non-testifying co-defendant’s statements that implicate a defendant are presumptively unreliable and their admission violates the Confrontation Clause. Douglas v. Alabama, 380 U.S. 415, 85 S.Ct. 1074, 13 L.Ed.2d 934 (1965). To overcome the presumption of unreliability, a prosecutor seeking admission of a non-testifying accomplice’s statements that incriminate a defendant must demonstrate that the statements bear adequate “indicia of reliability.” Ohio v. Roberts, 448 U.S. 56, 63-66, 100 S.Ct. 2531, 65 L.Ed.2d 597 (1980). As explained by the Supreme Court:
Reliability can be inferred without more in a case where the evidence falls within a firmly rooted hearsay exception. In other cases, the evidence must be excluded, at least absent a showing of particularized guarantees of trustworthiness.
Ohio v. Roberts, 448 U.S. at 66, 100 S.Ct. 2531.
In Lee v. Illinois, 476 U.S. 530, 106 S.Ct. 2056, 90 L.Ed.2d 514 (1986), the Supreme Court considered the case of a woman, Millie Lee (“Lee”), who, in a bench trial, was found guilty of murder by a trial judge who expressly relied on a non-testifying co-defendant’s confession implicating Lee. When questioned by police after her arrest, Lee said that she and her boyfriend, Edwin Thomas (“Thomas”), were arguing in the kitchen of the apartment that Lee shared with her aunt when a woman who was visiting the aunt entered the kitchen and chastised Lee and Thomas for arguing. Lee told police that (1) Thomas snapped, stabbing the woman in the back as she turned to leave the kitchen; (2) Lee then ran to the bedroom where she was threatened by her angry, knife-wielding aunt; and (3) Lee responded to her aunt’s threats by rushing back to the kitchen, grabbing a butcher knife, then returning to the bedroom where she repeatedly stabbed her aunt.
While Thomas corroborated many of the particulars of Lee’s confession, he provided one significant detail in his confession that was conspicuously absent from Lee’s account of the murders: he said that the murders were planned. According to Thomas, he and Lee formulated a preconceived plan to murder Lee’s aunt in order to stop the aunt’s harassment of Lee. Thomas explained that, when the presence of the aunt’s friend threatened to disrupt their plans to kill the aunt, he and Lee devised a plan to kill the friend also.
In finding Lee guilty of the two murders, the trial court expressly relied on the version of events described by Thomas in his post-arrest confession. On appeal, Lee argued unsuccessfully that her Confrontation Clause rights were violated by the trial court’s consideration of Thomas’ con[829]*829fession against her. The Supreme Court reversed the appellate court’s judgment affirming Lee’s convictions, holding “that Thomas’ statement, as the confession of an accomplice, was presumptively unreliable and that it did not bear sufficient independent ‘indicia of reliability’ to overcome that presumption.” Lee, 476 U.S. at 539, 106 S.Ct. 2056. The Court explained:
As we have consistently recognized, a codefendant’s confession is presumptively unreliable as to the passages detailing the defendant’s conduct or culpability because those passages may well be the product of the codefendant’s desire to shift or spread blame, curry favor, avenge himself, or divert attention to another. If those portions of the code-fendant’s purportedly “interlocking” statement which bear to any significant degree on the defendant’s participation in the crime are not thoroughly substantiated by the defendant’s own confession, the admission of the statement poses too serious a threat to the accuracy of the verdict to be countenanced by the Sixth Amendment. In other words, when the discrepancies between the statements are not insignificant, the co-defendant’s confession may not be admitted.
Lee, 476 U.S. at 545,106 S.Ct. 2056.
The Supreme Court in Lee did not expressly decide whether Thomas’ confession fell within a firmly rooted hearsay exception. Indeed, not until 1999 did the Court specifically hold that “[a] statement ... that falls into the category summarized in Lee — ‘a confession by an accomplice which incriminates a criminal defendant’...— does not come within a firmly rooted hearsay exception.” Lilly v. Virginia, 527 U.S. 116, 134, 119 S.Ct. 1887, 144 L.Ed.2d 117 (1999) (quoting Lee, 476 U.S. at 544 n. 5, 106 S.Ct. 2056) (citation omitted). The Court made clear, however, that it was merely making explicit in Lilly what was implicit in earlier cases:
Our holdings in Bruton v. United States, 391 U.S. 123, 88 S.Ct. 1620, 20 L.Ed.2d 476 (1968), Cruz v. New York, 481 U.S. 186, 107 S.Ct. 1714, 95 L.Ed.2d 162 (1987), Gray v. Maryland, 523 U.S. 185, 118 S.Ct. 1151, 140 L.Ed.2d 294 (1998), and Lee v. Illinois, 476 U.S. 530, 106 S.Ct. 2056, 90 L.Ed.2d 514 (1986), were all premised, explicitly or implicitly, on the principle that accomplice confessions that inculpate a criminal defendant are not per se admissible (and thus necessarily fall outside a firmly rooted hearsay exception), no matter how much those statements also incriminate the accomplice. If “genuinely” or “equally” inculpatory confessions of accomplices were ... per se admissible against criminal defendants, then the confessions in each of those cases would have been admissible, for each confession inculpated the accomplice equally in the crimes at issue. But the Court in Lee rejected the dissent’s position that a nontestify-ing accomplice’s confessions that are “unambiguously” against the accomplice’s penal interest are per se admissible, ... and we ruled in Bruton, Cruz, and Gray that such equally self-inculpa-tory statements are inadmissible against criminal defendants. Today we merely reaffirm these holdings and make explicit what was heretofore implicit.
Lilly, 527 U.S. at 134 n. 5, 119 S.Ct. 1887.
The defendant in Lilly, Benjamin Lee Lilly (“Lilly”), was convicted of murder and other crimes after the trial court admitted statements made by an accomplice under police questioning. The accomplice, who at trial invoked his Fifth Amendment privilege against self-incrimination, admitted to police that he was a participant in the crime spree that ended with the murder of a man, but he denied responsibility for the murder. He said that Lilly shot the victim. The trial court admitted the accomplice’s statements as declarations of [830]*830an unavailable witness against penal interest, overruling Lilly’s objections that admission of the statements would violate his Confrontation Clause rights. In affirming Lilly’s convictions, the Virginia Supreme Court found that the Confrontation Clause was satisfied because the accomplice’s statements fell within a firmly rooted exception to the hearsay rule under Virginia law, because the accomplice implicated himself as a participant in numerous crimes, and because the statements were independently corroborated by other evidence at trial. The Supreme Court reversed, rejecting all bases for the Virginia Supreme Court’s decision.
The Lilly Court first said that it was irrelevant that all statements against penal interest of an unavailable witness were treated as firmly rooted exceptions to the hearsay rule under Virginia law. Explaining that the question whether statements fall within a firmly rooted hearsay exception for Confrontation Clause purposes is a question of federal law, the Court held: “The decisive fact, which we make explicit today, is that accomplices’ confessions that inculpate a criminal defendant are not within a firmly rooted exception to the hearsay rule as that concept has been defined in our Confrontation Clause jurisprudence.” Lilly, 527 U.S. at 134, 119 S.Ct. 1887. The Court recognized, of course, that even though the confession in Lilly did not fall within a firmly rooted hearsay exception, the confession might nonetheless have been admissible if it had been supported by a showing of particularized guarantees of trustworthiness.
The Supreme Court went on, however, to discredit the purported guarantees of trustworthiness upon which the state courts relied in Lilly’s case. The Court, for example, rejected the notion that corroborative evidence provides the “particularized guarantees of trustworthiness” needed to support admission of an accomplice’s confession. Citing its 1990 decision in Idaho v. Wright, 497 U.S. 805, 110 S.Ct. 3139, 111 L.Ed.2d 638 (1990), the Court noted that it had squarely rejected the argument that evidence corroborating the truth of a hearsay statement may support a finding that the statement bears “particularized guarantees of trustworthiness.” Lilly, 527 U.S. at 138-139, 119 S.Ct. 1887. In Wright, 497 U.S. at 822, 110 S.Ct. 3139, the Court had said that “[t]o be admissible under the Confrontation Clause, hearsay evidence used to convict a defendant must possess indicia of reliability by virtue of its inherent trustworthiness, not by reference to other evidence at trial.”
The Supreme Court also rejected the notion that a self-inculpatory confession is trustworthy. Quoting its 1994 decision in Williamson v. United States, 512 U.S. 594, 599, 114 S.Ct. 2431, 129 L.Ed.2d 476 (1994) (holding — without reaching the Confrontation Clause issue — that an accomplice’s statement against his own penal interest was inadmissible against the defendant under the Federal Rules of Evidence), the Court wrote: “[TJhat a person is making a broadly self-inculpatory confession does not make more credible the confession’s non-self-inculpatory parts.” Lilly 527 U.S. at 139, 119 S.Ct. 1887. Noting the presumptive unreliability of the “non-self-in-culpatory” portions of an accomplice’s statement, the Court wrote, again quoting Williamson, 512 U.S. at 599-600, 114 S.Ct. 2431: “One of the most effective ways to lie is to mix falsehood with truth, especially truth that seems particularly persuasive because of its self-inculpatory nature.” Lilly, 527 U.S. at 133, 119 S.Ct. 1887.
Unpersuaded that the accomplice’s confession in Lilly was trustworthy either because it was self-incriminating or because it was supported by other corroborative evidence, the Supreme Court suggested that the circumstances relevant to the [831]*831trustworthiness inquiry are those that surround the making of an accomplice’s statement. The Court noted that “the historical underpinnings of the Confrontation Clause and the sweep of our prior confrontation cases offer one cogent reminder: It is highly unlikely that the presumptive unreliability that attaches to accomplices’ confessions that shift or spread blame can be effectively rebutted when the statements are given under conditions that implicate the core concerns of the old ex parte affidavit practice — that is, when the government is involved in the statements’ production, and when the statements describe past events and have not been subjected to adversarial testing.” Lilly, 527 U.S. at 137, 119 S.Ct. 1887. Applying the “historical underpinnings” to the confession at issue in Lilly, the Court concluded:
[The accomplice] was in custody for his involvement in, and knowledge of, serious crimes and made his statements under the supervision of governmental authorities. He was primarily responding to the officers’ leading questions, which were asked without any contemporaneous cross-examination by adverse parties. Thus, [the accomplice] had a natural motive to attempt to exculpate himself as much as possible.
Lilly, 527 U.S. at 139, 119 S.Ct. 1887. Under these circumstances, the Court found that admission of the co-defendant’s confession violated Lilly’s Confrontation Clause rights.
B.
In this case, the Guernsey County Court of Appeals rejected Calvert’s Confrontation Clause claim in a brief opinion that provides little analysis of federal law. The appellate court began its Confrontation Clause analysis by stating that the standard for admission of Mallory’s confession was governed by the Ohio evidentiary rule governing statements against interest and by a decision of the Ohio Supreme Court, State v. Gilliam, 70 Ohio St.3d 17, 635 N.E.2d 1242 (1994), cert. denied, 513 U.S. 1090, 115 S.Ct. 750, 130 L.Ed.2d 650 (1995). In Gilliam, the Ohio Supreme Court found that the admission of a non-testifying accomplice’s self-incriminating statement, which was corroborated by other witnesses, did not offend the Sixth Amendment’s Confrontation Clause because “the evidence was admissible pursuant to a firmly rooted exception to the hearsay rule” and because the self-inculpa-tory nature of the statement, coupled with other corroborative evidence, provided guarantees of trustworthiness. Gilliam, 635 N.E.2d at 1246. Convinced that the facts in Gilliam were “identical” to the facts in Calvert’s case, the Guernsey County Court of Appeals determined that the admission of Mallory’s confession against Calvert was proper. The court wrote:
Mr. Mallory admitted to hitting the victim with a stick and stabbing the victim ... Mr. Mallory concluded his statement by stating: “I’m guilty. I’m guilty. Guilty of murder.” We find Mr. Mallory’s statement was against his interest and clearly subjected him to “criminal liability.” Mr. Mallory’s statement demonstrated first hand knowledge of the incident ...
In examining Mr. Mallory’s statement for trustworthiness, we find the trial court had previously ruled after a suppression hearing that Mr. Mallory’s statement was admissible against Mr. Mallory ... Mr. Mallory’s description of the evening’s activities was collaborated [sic] by other evidence and witnesses. Mr. Mallory’s pajamas were found to be bloodstained by the Bureau of Criminal Identification and Investigation; three of the knives were found where Mr. Mallory said they would be and a broken walking stick was found in the victim’s apartment.
Upon review, we find the trial court properly applied the Gilliam case and [832]*832properly permitted the playing of Mr. Mallory’s taped statement.
Conspicuously absent from the Guernsey County court’s opinion was discussion and/or analysis of federal law, most notably the Lee v. Illinois decision. Under strikingly similar circumstances, the court in Gilliam and the Supreme Court in Lee had reached different conclusions regarding Confrontation Clause error. In both cases, the trial court admitted the confession of a non-testifying accomplice who under post-arrest police questioning admitted his guilt, who demonstrated first hand knowledge of the crimes, and whose testimony was corroborated by other evidence and witnesses. Whereas the Gilliam court found no Confrontation Clause error under these circumstances, the Supreme Court held that “on the record before us, there is no occasion to depart from the time-honored teaching that a codefendant’s confession inculpating the accused is inherently unreliable, and that convictions supported by such evidence violate the constitutional right of confrontation.” Lee, 476 U.S. at 546,106 S.Ct. 2056.
In reviewing Calvert’s habeas petition, the district court correctly concluded that, under federal law, the admissibility of Mallory’s statement depended upon what, if any, particularized guarantees of trustworthiness surrounded the making of the statement. Contrary to the state courts, the district court found no such guarantees surrounding the statement made by Mallory. Like the accomplice’s statement in Lee, Mallory’s statement was the product of in-custody interrogation for his involvement in, and knowledge of, serious crimes. Like the accomplice in Lee, Mallory made his statements under the supervision of governmental authorities, in response to police officers’ leading questions, which were asked without any contemporaneous cross-examination by adverse parties. Under these circumstances, the district court determined that there were no circumstantial guarantees of trustworthiness which would remove the presumption of unreliability and that, therefore, the admission of Mallory’s statement was a violation of the Confrontation Clause.
We have no trouble in concluding that the district court correctly determined that the admission of Mallory’s tape-recorded statement against Calvert violated Calvert’s Confrontation Clause rights. We also have no trouble in concluding that the Ohio courts acted “contrary to” clearly established Supreme Court precedent when they determined that the admission of Mallory’s statement did not violate the Confrontation Clause. We reject Respondent’s suggestion that the relevant law did not become clear until 1999, when, after Calvert’s appeal was decided, the Supreme Court decided in Lilly that statements against penal interests do not fall within a firmly rooted hearsay exception. At the time of Calvert’s trial, federal constitutional law, as clearly established by the Supreme Court in such cases as Lee v. Illinois and Idaho v. Wright, mandated the exclusion of Mallory’s tape-recorded confession as evidence against Calvert. The Ohio courts’ decisions to the contrary constituted error under the Confrontation Clause.
C.
Despite having found a Confrontation Clause violation, the district court denied relief because it found the error to be harmless.1 This court reviews a district [833]*833court’s decision as to harmless error de novo.
For purposes of federal habeas corpus review, a constitutional error that implicates trial procedures is considered harmless unless it had a “substantial and injurious effect or influence in determining the jury’s verdict.” Brecht v. Abrahamson, 507 U.S. 619, 113 S.Ct. 1710, 123 L.Ed.2d 353 (1993). This standard of review requires the reviewing court to examine the effect of the error on the jury rather than the sufficiency of the evidence at trial.
Before Brecht, courts had applied the harmless-beyond-a-reasonable-doubt standard enunciated in Chapman v. California, 386 U.S. 18, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967). Acknowledging that Brecht set the standard for determining harmless error, the district court nonetheless turned to a pre-Brecht case for a list of factors to be considered in making the harmless error assessment. Delaware v. Van Arsdall 475 U.S. 673, 684, 106 S.Ct. 1431, 89 L.Ed.2d 674 (1986). In Van Arsdall, in a Confrontation Clause context, the Court held:
The correct inquiry is whether, assuming that the damaging potential of the cross-examination were fully realized, a reviewing court might nonetheless say that the error was harmless beyond a reasonable doubt. Whether such an error is harmless in a particular case depends upon a host of factors, all readily accessible to reviewing courts. These factors include the importance of the witness’ testimony in the prosecution’s case, whether the testimony was cumulative, the presence or absence of evidence corroborating or contradicting the testimony of the witness on material points, the extent of cross-examination otherwise permitted, and, of course, the overall strength of the prosecution’s case.
Van Arsdall, 475 U.S. at 684, 106 S.Ct. 1431.
While acknowledging the Brecht standard, the district court considered the factors that the Court in Van Arsdall said should be considered in making the Chapman harmless-beyond-a-reasonable-doubt assessment. The district court’s discussion of the harmless error issue thus centered on the “significant evidence” against Calvert. The district court said nothing in its order about the effect of the Confrontation Clause error on the jury.
To prove aggravated murder under Ohio law, a prosecutor must prove, beyond a reasonable doubt, that a defendant “purposely, and with prior calculation and design, eause[d] the death of another.” Ohio Rev.Code 2903.01(A). “Prior calculation and design” became an element in 1974 when the Ohio General Assembly reclassified first-degree murder as “aggravated murder” and replaced the more traditional element of “deliberate and premeditated malice” with the requirement of “prior calculation and design.” The Ohio Jury Instructions define “prior calculation and design” as follows:
“Prior calculation and design” means that the purpose to cause the death was reached by a definite process of reasoning in advance of the homicide, which process of reasoning must have included a mental plan involving studied consideration of the method and the means and/or instrument with which to cause the death.
To constitute prior calculation, there must have been sufficient time and opportunity for the planning of an act of homicide, and the circumstances surrounding the homicide must show a scheme designed to carry out the calculated decision to cause the death. No definite period of time must elapse and no particular amount of consideration [834]*834must be given, but acting on the spur of the moment or after momentary consideration of the purpose to cause the death is not sufficient.
4 Ohio Jury Instructions § 503.01; see also State v. Coley, 93 Ohio St.3d 253, 754 N.E.2d 1129 (2001) (finding no merit to the defendant’s challenge to the trial court’s jury instruction — the pattern instruction from the Ohio Jury Instructions — defining “prior calculation and design”).
Our review of the evidence convinces us that Mallory’s tape-recorded confession was the most compelling piece of evidence against Calvert. Without Mallory’s statement, the jury heard that Mallory, not Calvert, threatened Bennett with an ax the evening before Bennett was murdered; that Bennett’s grandson saw that his grandfather was upset and concerned about Mallory’s threats just hours before the murder; that Calvert knew nothing about any plan to kill Bennett when he agreed to accompany Mallory to Bennett’s apartment; that, within minutes of entering Bennett’s apartment, Mallory bludgeoned Bennett with a hatchet and cut him across the throat with a butcher knife; that Calvert, who was near Bennett at the time, “got out” when the blood started flying; that Bennett was still alive when Calvert left the scene; that Mallory disposed of the murder weapons; that Calvert and Mallory took a cab to a bar not long after Calvert left Bennett’s apartment; that Calvert returned to Bennett’s neighbor’s apartment the next morning still dressed in the clothes he was wearing the night before; that his clothes were stained with Bennett’s blood; that traces of Bennett’s blood type were found in nail scrapings from Calvert’s left-hand; and that Calvert was cooperative when police officers found him in Bennett’s neighbor’s apartment the morning after the murder. In addition, the jury apparently heard from the cab driver that Calvert, who was in good spirits during the cab ride to the bar, said to Mallory: “We showed him.” The jury also apparently heard that, late on the evening of the murder, Calvert told a friend that he had hit a black man (Bennett was white) with a hatchet but did not know if the man was dead.2 The jury did not hear, from anyone but Mallory, that Calvert caused the death of Bennett with prior calculation and design.
Defense counsel argued to the jury that Mallory severely wounded Bennett in Calvert’s presence, leaving traces of blood on his clothes and his hand; that Calvert “got out” while Bennett was still alive; that Mallory left the bar early and later, dressed in his pajamas, returned to Bennett’s apartment, broke open the window to unlock the door, and finished off Bennett by stabbing him repeatedly with a knife. Had Mallory’s statement not been admitted, the evidence against Calvert was circumstantial and not inconsistent -with Calvert’s argument that he was present when Bennett was initially wounded but was not present when Bennett was later killed. Had Mallory’s statement not been admitted, the prosecutor had no direct evidence that Calvert acted with prior calculation and design.
In Richardson v. Marsh, 481 U.S. 200, 208, 107 S.Ct. 1702, 95 L.Ed.2d 176 (1987), the Supreme Court emphasized that confessions which expressly implicate a defendant are “powerfully incriminating.” Indeed, specific testimony that “the defendant helped me plan and commit the crime” is much more vivid than any evi[835]*835dence that is incriminating only when the jury makes an inference. In this case, without Mallory’s statement, the jury would have had to infer Calvert’s guilt. With the admission of Mallory’s statement, the jury had no need to engage in any inferences at all. See Bulls v. Jones, 274 F.3d 329, 336 (6th Cir.2001) (holding that admission of non-testifying co-defendant’s statement, which provided direct evidence — the only direct evidence — of malice, had substantial and injurious effect in determining jury’s verdict).
In this case, Mallory’s statement may have been precisely the evidence that convinced the jury that Calvert “purposely, and with prior calculation and design,” caused the death of Bennett. We must conclude, therefore, that the admission of Mallory’s statement had a substantial and injurious influence in determining the jury’s verdict. Accordingly, we REVERSE the district court’s denial of habe-as relief and REMAND with directions to issue a conditional writ of habeas corpus releasing Calvert from custody, unless he is retried within a reasonable period of time to be determined by the district court.
CONCURRENCE