dissenting.
When an attorney calls forward an expert, especially an expert asked to provide mitigating evidence when a defendant’s life hangs in the balance, the attorney has an obligation to ensure that the expert knows about that which she speaks. When the majority declares that “[w]e will not find counsel deficient simply because they did not succeed in discovering his brain damage or pursue unspecified, alternate avenues (which may or may not have revealed the brain damage),” Maj. Op. at 625, they find no fault in the actions of counsel who, in the face of numerous indicators of brain damage, inexcusably failed to ensure that their expert actually tested for the organic brain disorder that she claimed to b$ unable to find. I believe that the majority’s elevation of form over substance wrongly excuses ineffective assistance of counsel; simply presenting an expert who is a doctor does not absolve counsel from an obligation to grasp the bare rudiments of the expert’s testimony. Because I conclude that Fautenberry’s counsel was ineffective in the penalty stage of his trial, I respectfully dissent.
In order to establish ineffective assistance of counsel on post-conviction review, “[f]irst, petitioner must show that ‘counsel’s representation fell below an objective standard of reasonableness.’ Second, petitioner must show that ‘there is a reasonable probability that, but for counsel’s unprofessional errors, the result of the proceeding would have been different.’” Darden v. Wainwright, 477 U.S. 168, 184, 106 S.Ct. 2464, 91 L.Ed.2d 144 (1986) (citations omitted) (quoting Strickland v. Washington, 466 U.S. 668, 668, 694, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984)).
Because this case is governed by the Antiterrorism and Effective Death Penalty Act of 1996 (“AEDPA”), codified principally at 28 U.S.C. § 2254(d), we can grant relief only if the state-court proceedings “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)(1). However, where “the state court did not asséss the merits of a claim properly raised in a habeas petition, the deference due under AEDPA does not apply.” Maples v. Stegall, 340 F.3d 433, 436 (6th Cir.2003). I believe that Fautenberry has established -both deficient performance of counsel and that the deficient performance prejudiced the mitigation phase of his trial. Furthermore, I conclude that -the Ohio courts’ determination that his counsel was not deficient was contrary to clearly established federal law.
I. Deficient Performance of Counsel
Despite the majority’s attempts to portray Fautenberry’s claim as a simple question of whether or not his counsel exerted the appropriate level of effort in investigating potential mitigation defenses, this case actually presents a different question: Does counsel have an obligation to ensure that their own expert witness has fully investigated whether the defendant suffers from an organic brain impairment before the expert witness can testify that he does not? While the majority is content to *644state that “any inadequacies in Dr. Schmidtgoessling’s expert assistance ... cannot be the basis for a meritorious ineffective-assistance claim,” Maj. Op. at 626,1 believe that simply hiring any so-called expert, regardless of the quality of the expert’s work, does not entitle counsel to a free pass with regards to their own performance at the mitigation phase.
A. Notice of Brain Damage
When defense counsel is on notice of past incidents that would suggest brain damage, “[w]e can conceive of no rational trial strategy that would justify the failure of [defense] counsel to investigate and present evidence of his brain impairment. ...” Frazier v. Huffman, 343 F.3d 780, 794 (6th Cir.2003) (discussing how counsel did no investigation into the presence of an organic brain impairment after learning from medical records that the defendant fell from a ladder), cert. denied, 541 U.S. 1095, 124 S.Ct. 2815, 159 L.Ed.2d 261 (2004). In this case, however, we are not asked to decide whether counsel investigated — Fautenberry’s counsel did seek psychiatric evaluations from both Dr. Nancy Schmidtgoessling (“Dr. Schmidt-goessling”) and Dr. James Tanley (“Dr. Tanley”) — instead we must peer into the adequacy of counsel’s investigation.
“In assessing counsel’s performance, a court must thus consider whether counsel adequately followed up on the ‘leads’ that were available to them.” Haliym v. Mitchell, 492 F.3d 680, 712 (6th Cir.2007). One such lead for defense attorneys is a history of head injuries; “head injuries were a ‘red flag’ to those in the area of psycho-social investigation, signifying the need for additional testing....” Id. at 710 (crediting an expert’s view regarding the salience of a defendant’s head injuries). For instance, in Haliym, “Petitioner’s attorneys were on notice that Petitioner had shot himself in the left temple, which should have strongly suggested the need to investigate whether Petitioner had a mental defect.” Id. at 714.
Fautenberry’s counsel, while perhaps lacking the smoking gun of a brain injury present in Haliym, certainly had ample notice of the stark facts of Fautenberry’s life that strongly suggested the possibility of brain damage. First, his counsel was aware that physical abuse was a frequent element in Fautenberry’s childhood. Fau-tenberry suffered abuse at the hands of several people over the course of his youth. See, e.g., J.A. at 649 (Mitig. Hr’g of Sept. 14, 1992, Unsworn Stmt, of John J. Fautenberry at 277:3-18); J.A. at 652 (Fautenberry at 280:7-23). A family friend testified that one abuser, Donald Langdon, “back-handed [Fautenberryl’s head against the wall several times. [Fauten-berry] would appear disoriented after Donald hit him.” J.A. at 1996 (Aff. of Kenneth Corcoran at ¶ 4). The abuse was so frequent “[a]ccording to [Fautenberry’s sister], she and [Fautenberry] grew up thinking that getting hit was normal.” J.A. at 2190 (Aff. of Pamela Swanson at ¶ 14).
In addition to the abuse, there were two physically traumatic events that are strongly suggestive of the possibility of brain damage. The first incident was when Fautenberry “was hit in the back of the head by a wooden swing, and his recollection is that he lost consciousness, although for an uncertain amount of time.” J.A. at 1916 (Neuropsychological Evaluation by Dr. Jeffery L. Smalldon at 8). Of the incident, one observer recalled that “when [Fautenberry] was around seven years old, he got hit on the head with a swing. [Fautenberry] bled profusely. He was taken to a local hospital in Norwich-town, Connecticut. It was around the time of the injury that [Fautenberry]’s behavior changed. [Fautenberry] became mean to *645the people around him.” J.A. at 2185-86 (Aff. of Louise Corcoran at ¶ 20). Fauten-berry may have been unconscious for up to seven hours and may have suffered a fractured skull, J.A. at 1917 (Dr. Smalldon at 9), but some records suggest that the damage may have been less severe, see J.A. at 1974 (Rep. of Med. Hist.) (noting that the swing injury resulted in neither a concussion nor a fracture). Regardless of the exact details, the incident still provided notice to Fautenberry’s attorneys of the possibility of an organic brain defect.
“The second major head trauma occurred when [Fautenberry] was in his late-teens and serving in the U.S. Navy. He reports that he was laying flat atop a pontoon, reaching down over the side to retrieve a cigarette from a lower level, when his head became wedged in between the side of the pontoon and an approaching ship. He recalls that he was unable to breath [sic],, and that he fully expected that his head was about to be crushed.” J.A. at 1917 (Dr. Smalldon at 9). After the incident, military doctors took x-rays of Fautenberry’s skull and found no sign of a fracture. J.A. at 1977 (Med. Rec.).
The last element that might have served as a red flag for Fautenberry’s counsel is the présence of mental illness in his family. Fautenberry’s mother took anti-depressants, J.A. at 2188 (Swanson at ¶ 5), and Fautenberry’s grandmother “suffered from mood swings,” J.A. at 2185 (Louise Corcoran at ¶ 18).
None of these elements — the abuse, the traumatic head injuries, or the family history — are conclusive of anything. When combined with Fautenberry’s “history of intermittent, severe headaches,” J.A. at 1916 (Dr. Smalldon at 8), however, it should have established for his attorneys that an investigation into Fautenberry’s mental health was of paramount importance for the mitigation phase of his trial. Indeed, it appears that Fautenberry’s attorneys were not unaware of the issue; Fautenberry’s counsel requested neurop-sychological testing because “it is suggested that the Defendant may be suffering from some organic impairment or underlying organic disorder.” J.A. at 915 (Mot. for Neurological Exam.). In response to his counsel’s request, the trial court ordered Dr. Schmidtgoessling to conduct a neurological examination, J.A. at 1065 (Entry Ordering Neurological Exam.), and authorized funds for a psychologist and a mitigation expert, J.A. at 1066 (Granting Mot. to Employ Dr. Tieger); J.A. at 1067 (Granting Mot. to Employ Dr. Shorr). Simply requesting neuropsychological testing, however, does not in itself guarantee that counsel’s performance was effective.
B. An Obligation to Investigate
Many of the cases that have found ineffective assistance of counsel at the mitigation phase are cases where the defendant’s attorneys failed to invest even a minimal amount of time into discovering a brain defect when they were alerted to the real possibility that one might exist. Such a “complete failure to investigate mitigating evidence constitutes ineffective assistance of counsel.” Mason v. Mitchell, 320 F.3d 604, 620, 626 (6th Cir.2003); see also Morales v. Mitchell, 507 F.3d 916, 931-35 (6th Cir.2007) (finding ineffective assistance when trial counsel failed to conduct interviews with various family members and friends, each possessing mitigating evidence). Thus, this court has found ineffective assistance of counsel when the defendant’s attorneys were told that there was a potential mental-health issue but never consulted with any mental-health expert, see Harries v. Bell, 417 F.3d 631, 638 (6th Cir.2005), and when “Petitioner’s counsel ... failed to diagnose Petitioner’s brain injury, despite the fact that they knew or *646should have known that Petitioner shot himself in the head,” because the defendant’s attorneys never provided the defendant with an independent psychiatric analysis, Haliym, 492 F.3d at 715-16.
Just because the starkest examples of counsel’s failures are the ones most likely to find disapprobation by this court does not mean that counsel is ineffective only when they fail to do the most minimal investigation. Instead, there is a sliding scale for evaluating counsel’s obligation to investigate. On the one hand, the duty to investigate does not encompass a duty to overturn every stone in the pursuit of every remote possibility; “reasonably diligent counsel may draw a line when they have good reason to think further investigation would be a waste.” Rompilla v. Beard, 545 U.S. 374, 383, 125 S.Ct. 2456, 162 L.Ed.2d 360 (2005). On the other hand, “[c]ounsel’s constitutional duty to investigate a defendant’s background in preparation for the sentencing phase of a capital trial is ‘well-established.’ ” Harries, 417 F.3d at 637 (quoting Coleman v. Mitchell, 268 F.3d 417, 449 (6th Cir.2001)). Furthermore, that the defendant could be sentenced to death “magnifies counsel’s responsibility to investigate.” Id.; Guidelines FOR the Appointment and Performance of Defense Counsel in Death Penalty Cases, Guideline 10.7 Commentary (Am. Bar Ass’n, Rev. Ed.2003) (“2003 Guidelines”) (“This duty [to investigate] is intensified (as are many duties) by the unique nature of the death penalty ....").1
In applying this sliding scale for evaluating counsel’s duty, the importance and relevance of the potential topic for investigation can make counsel’s obligation “particularly pressing,” Rompilla, 545 U.S. at 386, 125 S.Ct. 2456, while the difficulty in obtaining or the speculative nature of the potential information may mean that counsel is less culpable for a failure to investigate. See id. at 386 n. 4, 125 S.Ct. 2456. Thus, in Rompilla, the Supreme Court found ineffective assistance of counsel when the Court concluded that the existence of numerous red flags made the potential existence of an extreme emotional disturbance more than remote speculation and of great significance for the defendant’s case. See Rompilla, 545 U.S. at 392-93, 125 S.Ct. 2456.
In the instant case, the possibility that Fautenberry suffered from an organic brain defect was certainly not rampant speculation given all of the red flags that Fautenberry’s counsel should have noticed. Accordingly, Fautenberry’s counsel were not under some cursory obligation to investigate the potential for brain damage but were instead under a significant and pressing obligation to do so.
C. Fautenberry’s Counsel’s Investigation
Although Fautenberry’s counsel were under a significant and pressing obligation to pursue the possibility that their client suffered from an organic brain defect, I conclude that they failed to live up to their obligation. The mitigation testimony that *647they presented on Fautenberry’s mental condition was that of Dr. Schmidtgoess-ling. In order to evaluate Fautenberry, Dr. Sehmidtgoessling conducted a series of tests: “I did a Raven, which is a kind of a screening test for certain lines of organic functioning. A Bender, MMPI, Trails A and B, all those things looking at his intellectual and cognitive functioning. I did an MMPI. That was the bulk of the information that we had in terms of preparing our evaluation of Mr. Fautenberry.” J.A. at 669 (Mitig. Hr’g of Sept. 14, 1992, Un-sworn Stmt, of Dr. Sehmidtgoessling at 297:12-18).
On the basis of her evaluation, Dr. Sehmidtgoessling stated her conclusion in no uncertain terms: “In short, the available psychological testing yielded no signs suggestive of organic impairment.” J.A. at 1275 (Dr. Sehmidtgoessling Rep. at 3). Fautenberry’s counsel, for inexplicable reasons, did their best to impress this conclusion upon the sentencing panel; twice on direct examination, Fautenberry’s counsel prompted Sehmidtgoessling to reaffirm her conclusion. J.A. at 669 (Hr’g, Dr. Sehmidtgoessling at 297:23-24) (“As far as I could tell there were no signs of organic impairment ... ”); J.A. at 672-73 (Hr’g, Dr. Sehmidtgoessling at 300:24-301:3) (“As an adult now, you know, in terms of a psychological description, I would say that there is no sign of any major mental disorder. We are not talking of any schizophrenia or manic depression, nothing like that.”). The government, in contrast, actually elicited a more favorable analysis from Dr. Schmidtgoess-ling, provoking her to admit that Fauten-berry did suffer from “a severe personality disorder but not as I understand it a disease or defect.” J.A. at 684 (Hr’g, Dr. Sehmidtgoessling at 312:21-24). On redirect, again Fautenberry’s attorneys provoked Dr. Sehmidtgoessling to emphasize her adverse conclusion:
Q. Mr. Tolbert asked you about the mental disease or defect and your testimony was that John Fautenber-ry is not bipolar, correct?
A. Correct.
Q. He is not Schizo?
A. Correct.
Q. He does not have this mental disease or defect, is that correct?
A. The way I understand that term, that’s right.
Q. Now I’m sure there are other mental diseases and defects than the two I have mentioned, is that correct?
A. That pretty well covers it, though.
Q. Okay, so to qualify for this section under mental disease or defect I almost have to be cubbyholed into that, is that accurate, I have to have one of those two?
A. Yeah.
J.A. at 694-95 (Hr’g, Dr. Sehmidtgoessling at 322:15-323:8). Fautenberry’s counsel, therefore, while under an obligation to investigate fully the possibility that Fauten-berry may have an organic mental defect, concluded that there was no defect and presented a witness during the mitigation phase who impressed that conclusion upon the sentencing panel three separate times.
D. Use of Dr. Sehmidtgoessling was Defective Assistance of Counsel
Fautenberry’s counsel’s reliance upon the testimony of Dr. Sehmidtgoessling was defective. My objection to their reliance on her testimony, however, is not that counsel repeatedly emphasized adverse testimony, nor is it about the accuracy of her analysis; instead, I believe that her testimony was problematic because Fau-tenberry’s counsel failed to possess even a rudimentary grasp of Dr. Sehmidtgoess-ling’s work sufficient to assess whether her *648conclusion was fairly grounded in her testing.
On post-conviction review, Fautenberry has presented the opinion of Dr. Jeffrey Smalldon (“Dr. Smalldon”) to establish that Dr. Schmidtgoessling’s testing was insufficient to support her conclusion:
In fact, however, no recognized neurop-sychological test battery was ever performed, and thus there was not available a sufficient body of data to justify a conclusion — one way or the other — • about the presence of brain impairment. No professional with specialized training and experience in neuropsychological assessment would expect to lean from the limited battery of tests administered by Dr. Schmidtgoessling whether Mr. Fautenberry is brain impaired. [The tests Dr. Schmidtgoessling administered] do not at present enjoy widely-accepted status even as effective means of ‘screening for’ organic brain impairment, and that data derived from this battery, while perhaps suggestive, is not sufficient to rule out the presence of such impairment.
J.A. at 1914 (Dr. Smalldon at 6) (emphasis added). Of course, the assertion that Dr. Schmidtgoessling’s conclusion had no foundation in her testing is not true just because Fautenberry and his counsel have now found an expert willing to assert as much. We do not need to take Dr. Small-don’s word on the matter; Dr. Schmidt-goessling herself has previously admitted in another case that “neither she nor any other staff member at the court’s psychiatric clinic were qualified to conduct the type of testing and evaluation that was required to diagnose Petitioner with oi-ganic brain damage for the purpose of showing the effect of that factor at mitigation.” Powell v. Collins, 332 F.3d 376, 395 (6th Cir.2003); see also id. at 384 (“Dr. Schmidtgoessling admitted that she was ‘definitely not equipped’ to conduct the necessary neu-ropsychological testing for this phase of Petitioner’s case.”). Thus, Fautenberry’s counsel repeatedly emphasized to the sentencing panel Dr. Sehmidtgoessling’s conclusion of mental normalcy, which, as it turns out, she most likely had not conclusively established. Had Fautenberry’s counsel been aware of the shaky foundations underlying Schmidtgoessling’s conclusion, his counsel might have chosen not to provoke repeatedly her erroneous assertion and they might have continued to pursue a more conclusive determination. See id. at 400 (“Dr. Schmidtgoessling’s inability to provide conclusive evidence regarding organic brain damage made other avenues of investigation all the more crucial.”).
Counsel presenting mitigating evidence do not need doctorates in psychology to ply their craft; but just as counsel are required to have a basic understanding of forensic science when presenting forensic evidence, Fautenberry’s counsel cannot call a psychologist to testify while counsel are ignorant of the foundations of her testimony and then hide behind technical psychological terms such as “MMPI” or “Trails A and B.” Recently, in the context of an arson prosecution, we have held that a lawyer must possess a basic understanding of the science that underlies his witness’s testimony.
Even more importantly, it is inconceivable that a reasonably competent attorney would have failed to know what his expert was doing to test the State’s arson conclusion, would have failed to work with the expert to understand the basics of the science involved, at least for purposes of cross-examining the State’s experts, and would have failed to inquire about why his expert agreed with the State. A lawyer cannot be deemed effective where he hires an ex*649pert consultant and then either willfully or negligently keeps himself in the dark about what that expert is doing, and what the basis for the expert’s opinion is.
Richey v. Bradshaw, 498 F.3d 344, 362-63 (6th Cir.2007) (emphasis added) (citation omitted). Fautenberry’s attorneys were thus under an obligation to understand the basic foundations of Dr. Schmidtgoess-ling’s testimony, but they failed to fulfill this obligation.
While “ ‘[a]n attorney is not required to be so expert in psychiatry’ ” so that he could diagnose a medical condition in the absence of any indicators, Clark v. Mitchell, 425 F.3d 270, 286 (6th Cir.2005) (alteration in original), that does not excuse deficient attorney performance when red flags alert him to the possibility of a mental deficiency. We have repeatedly denied petitions for habeas where the petitioner attempted to blame his attorneys for failing to diagnose brain damage despite a total absence of red flags indicating the potential for any brain damage. See, e.g., Clark, 425 F.3d at 285 (concluding that “[i]t was not unreasonable for Clark’s counsel, untrained in the field of mental health, to rely on the opinions of these professionals” who concluded that there was no brain damage); Campbell v. Coyle, 260 F.3d 531, 555 (6th Cir.2001) (“Even though Dr. Chiappone as a trained psychologist failed to detect any evidence of PTSD, Campbell asks us to declare that his counsel’s independent failure to make the same diagnosis is an objectively unreasonable mistake, depriving him of his Sixth Amendment right to the effective assistance of counsel. There is no evidence that Dr. Chiappone was incompetent, or that Campbell’s lawyers had any reason to question Chiappone’s professional qualifications.”).2 An attorney, therefore, does not need to possess the skill to diagnose his client’s hidden ailments and can generally rely on the expertise of a licensed practitioner. See Lundgren v. Mitchell, 440 F.3d 754, 772 (6th Cir.2006).
For an attorney to fulfill his duty in the mitigation phase, one trained in law and advocacy need not also be expert in medicine, but a lack of training in medicine cannot excuse a failure of expertise in the law. Normally, “[counsel's diligence in obtaining not just the constitutionally mandated single mental health expert, but two mental health experts, shows that counsel engaged in a reasonable investigation....” Lundgren, 440 F.3d at 772. “But the mere hiring of an expert is meaningless” when counsel fails to use the expert’s knowledge to understand the nature and limits of the expert’s testimony. Richey, 498 F.3d at 362. Fautenberry’s counsel could not be faulted for not diagnosing Fautenberry’s mental impairments on their own, but once they decided to present a psychologist to the sentencing panel, they were under an obligation to understand the basics of their witness’s testimony. See Richey, 498 F.3d at 362-63; Skaggs v. Parker, 235 F.3d 261, 269 (6th Cir.2000) (stating that counsel had “a responsibility to present meaningful mitigating evidence” when the court concluded that it was ineffective assistance of counsel when defense attorneys called a neurop-scyhologist who had falsified his credentials and whom counsel knew had previous*650ly done a laughable job at the first trial); Driscoll v. Delo, 71 F.3d 701, 709 (8th Cir.1995) (holding that defense counsel was defective for failing “to understand the laboratory tests performed and the inferences that one could logically draw from the results” when challenging the state’s expert). Because they failed to grasp the basics of Dr. Schmidtgoessling’s testimony, I conclude that Fautenberry’s counsel were defective.
This is not, in contrast to the majority’s suggestion, a question of whether or not Dr. Schmidtgoessling was correct in her analysis. Instead, the question should be whether Fautenberry’s attorneys were sufficiently able to evaluate the correctness of Dr. Schmidtgoessling’s analysis. Had Fautenberry’s counsel been better equipped to scrutinize Dr. Schmidtgoess-ling’s testimony and recognized the need for further investigation, they might have discovered evidence of an organic brain impairment. Fautenberry has now presented the statement of one medical professional who has reached quite a different conclusion than Dr. Schmidtgoessling: “It is my opinion, offered with reasonable psychological certainty, that Mr. Fautenberry is brain impaired.” J.A. at 1922 (Dr. Smalldon at 14). Dr. Smalldon concluded that the impairment was only “mild,” but added that it was “by no means insignificant. ‘Mild’ when used as a descriptive adjective in this context only serves to differentiate one classification of brain injury from other classifications where the associated deficits might be even more dramatically apparent.” J.A. at 1922-23 (Dr. Smalldon at 14-15). According to Dr. Smalldon, “[bjrain impairment of the sort that is clearly apparent in Mr. Fautenber-ry’s case can also cause serious problems in such areas of day-to-day functioning as impulse control; modulation of affect; planning; problem-solving; and the capacity to tolerate frustration.” J.A. at 1923 (Dr. Smalldon at 15). Thus, there was readily available to Fautenberry’s attorneys significant mitigating evidence, and the failure to collect and present readily obtainable evidence of this sort is classified as nothing short of an “abdication of advocacy.” Powell, 332 F.3d at 399-400.
E. Fautenberry’s Uncooperative Behavior
The majority would excuse any failure on the part Fautenberry’s counsel on the basis that Fautenberry refused to cooperate with Dr. Tanley. As the majority declares: “Had Fautenberry not impeded Dr. Tanley’s examination, the doctor presumably would have discovered, verified, and revealed any such brain damage.” Maj. Op. at 625. The fault, however, for any failure to discover Fautenberry’s brain damage, given all of the red flags in his medical history, cannot be placed at the feet of a man who is supposedly mentally impaired. Instead, aware of the various indicators of an organic brain impairment, it was solely the responsibility of Fauten-berry’s attorneys to pursue zealously evidence of an impairment.
The American Bar Association’s (“ABA”) Guidelines that establish the appropriate conduct for defense counsel in death-penalty cases specifically state that mitigating evidence must be pursued “regardless of any statement by the client that evidence bearing upon penalty is not to be collected or presented.” 2003 Guidelines, Guideline 10.7(A)(2); id. at Guideline 10.7. commentary (“The duty to investigate exists regardless of the expressed desires of a client.”); Guidelines FOR the Appointment AND PERFORMANCE OF DEFENSE COUNSEL in Death Penalty Cases, Guideline 11.4.1(C) (Am. Bar Ass’n, 1983) (“1983 Guidelines”). While the majority would excuse otherwise deficient performance when counsel claims that their client made *651it difficult for them to find mitigating evidence, the ABA demands that defense counsel go beyond the barriers that their client may erect. The ABA even recognizes that when pursuing mitigating evidence, “[ojbtaining such information typically requires overcoming considerable barriers, such as shame, denial, and repression, as well as other mental or emotional impairments from which the client may suffer.” 2003 Guidelines, 10.7 commentary. While the ABA recognizes the challenges that defense counsel may face and exhorts counsel to continue pursuing mitigating evidence in the face of those challenges, the majority condones a halfhearted effort.
Our precedent, like the ABA guidelines, also directs counsel to persevere in the search for mitigating evidence despite difficulties that the defendant may himself create. For instance, the Supreme Court found ineffective assistance of counsel when the defendant was “even actively obstructive by sending counsel off on false leads.” Rompilla, 545 U.S. at 381, 125 S.Ct. 2456. Similarly, we have noted that “ ‘defendant resistance to disclosure of information does not excuse counsel’s duty to independently investigate.’ ” Harries, 417 F.3d at 638 (quoting Coleman, 268 F.3d at 449-50). In a case where we noted that “[tjrial counsel cannot be faulted for their client’s lack of cooperation,” Lorraine v. Coyle, 291 F.3d 416, 435 (6th Cir.2002), cert. denied, 538 U.S. 947, 123 S.Ct. 1621, 155 L.Ed.2d 489 (2003), neither could we fault trial counsel for a lack of effort; in that case, counsel arranged for an EEG, a CAT Scan, and an MRI, and counsel persisted in eventually obtaining the test results even when the defendant initially refused. Similarly, in Byrd v. Collins, 209 F.3d 486 (6th Cir.2000), cert. denied, 531 U.S. 1082, 121 S.Ct. 786, 148 L.Ed.2d 682 (2001), counsel was not held responsible when the defendant refused to allow a psychologist or psychiatrist to interview him, id. at 526-27, because there were no red flags indicating the potential for brain damage and increasing counsel’s obligations. As I have already stated, counsel does not have an obligation to pursue outlandish leads; however, when there are indicators of a significant, potential mitigating defense, counsel has an obligation to pursue it.
Regardless of whether or not there was a breakdown in communication between Fautenberry and his attorneys, his attorneys remained obligated to investigate fully the potential presence of an organic brain impairment. It is my conclusion, therefore, that Fautenberry has established that his counsel were defective: his counsel was on notice that there was a significant possibility of brain damage, they were under an obligation to investigate fully that possibility, they failed to comprehend the basic scientific limits of Dr. Schmidtgoessling’s testimony, and their failure is not excused by Fautenber-ry’s uncooperative actions.
The last court in Ohio to address Fau-tenberry’s ineffective-assistance claims was the Court of Appeals for Ohio’s First District considering Fautenberry’s petition for state-postconviction relief. The state court addressed only whether Fautenber-ry’s counsel was defective and concluded that Fautenberry’s resistance to meeting with Dr. Tanley precluded any finding of defective performance. See J.A. at 2325-29 (Op. of Dec. 31, 1998 at 3-7). The court stated that counsel’s failure to do more, “even if true, does not make the consequences of Fautenberry’s own recalcitrance imputable to his attorneys, nor does it cast their performance outside the ‘wide range of reasonable professional assistance.’ ” J.A. at 2328 (Op. at 6). While the Ohio Court of Appeals’s holding is clearly contrary to Rompilla, Rompilla *652was not decided until 2005, well after the Ohio Court of Appeals’s 1998 decision. Rompilla, however, was only the most recent case that the Supreme Court has decided on this matter; Strickland and Burger v. Kemp, 483 U.S. 776, 107 S.Ct. 3114, 97 L.Ed.2d 638 (1987), both held that counsel is not deficient when they fail to investigate mitigating evidence only when they reasonably believe that such efforts would be wasted. See Burger, 483 U.S. at 794-95, 107 S.Ct. 3114; Strickland, 466 U.S. at 699, 104 S.Ct. 2052. Although these cases do not specifically address dealing with an obstinate client, such specificity is not necessary. “[CJlearly established law under [AEDPA] encompasses more than just bright-line rules laid down by the [Supreme] Court. It also clearly includes legal principles and standards enunciated in the Court’s decisions.” Taylor v. Withrow, 288 F.3d 846, 850-51 (6th Cir.), cert. denied, 537 U.S. 1007, 123 S.Ct. 490, 154 L.Ed.2d 406 (2002). “The lack of an explicit statement” of a rule “is not determinative” because “[t]he Court has made clear that its relevant precedents include not only bright-line rules but also the legal principles and standards flowing from precedent.” Id. at 852. Because Fautenberry’s counsel could not have reasonably believed that' a medical examination would have been fruitless, their obligation to pursue that evidence did not wane simply because their client was being difficult; holding otherwise is contrary to clearly established federal law.
II. The Prejudice Resulting From Counsel’s Deficient Performance
If Fautenberry is to prevail on his ineffective assistance of counsel claim, not only must he prove that his counsel were defective, but also he must show that counsel’s defectiveness was prejudicial. Because the Ohio Court of Appeals did not reach this issue, we apply no deference under AEDPA. Maples, 340 F.3d at 436. The majority states that even if Fautenberry had presented evidence of an organic brain impairment, “[i]t is highly unlikely that this sort of evidence would have altered the three-judge panel’s decision to impose the death sentence for Fautenberry’s murder of Daron, which they found was ‘contemplated and calculating’ — a conclusion that is not at all mitigated or reduced by the traits associated with or the side effects of organic brain disorder.” Maj. Op. at 627. I must disagree; we have repeatedly held that evidence of a brain impairment is very significant during mitigation. Furthermore, the sentencing panel’s conclusion that the murder was “contemplated and calculating” cannot be divorced from the fact that the panel was repeatedly told that Fautenberry was mentally healthy; evidence of a brain impairment would almost certainly cast doubt on Fau-tenberry’s abilities to contemplate and calculate and would certainly raise questions of culpability.
The hurdle for establishing prejudice is not high: “Petitioner ‘need not show that counsel’s deficient conduct more likely than not altered the outcome in the case,’ rather, only that ‘there is a reasonable probability that, but for counsel’s unprofessional errors, the result of the proceeding would have been different.’” Lundgren, 440 F.3d at 770 (quoting Strickland, 466 U.S. at 694, 104 S.Ct. 2052). “Ohio is a ‘weighing’ state, which means that the aggravating circumstances must outweigh the mitigating factors in order to impose the death penalty. Under federal law, one juror may prevent the death penalty by finding that mitigating factors outweigh aggravating factors. As the Supreme Court recently said in Wiggins, the ‘prejudice’ prong is satisfied if ‘there is a reasonable probability that at least one juror *653would have struck a different balance.’” Id. (quoting Wiggins v. Smith, 539 U.S. 510, 523-28, 123 S.Ct. 2527, 156 L.Ed.2d 471 (2003)). Although Fautenberry was sentenced by a panel of three judges and not a jury, Ohio similarly requires a panel of judges to be unanimous in a death sentence. Ohio Rev.Code Ann. § 2929.03(D)(3).
Our precedent has repeatedly emphasized the significance of evidence of an organic brain impairment during the penalty phase. In Harries, we held that it was reasonably probable that evidence of frontal lobe damage would have changed the sentencing outcome. See Harries, 417 F.3d at 641. In Frazier, we noted that there was a significant “probability that the jury would find that a murderer who suffers from a functional brain impairment is less morally culpable than one who does not, even if the brain impairment did not ‘cause’ Frazier to murder Skiba.” Frazier, 343 F.3d at 798. And in Glenn v. Tate, 71 F.3d 1204 (6th Cir.1995), we suggested that a jury’s sentence would change when presented with evidence of an organic brain defect. See id. at 1211 (“John Glenn’s sentencing proceeding can hardly be relied upon as having produced a just result when the jurors were given to understand, in the unchallenged report of Dr. Siddall, that the crime was not the product of mental retardation or organic brain disease.” (footnote omitted)). Given the importance of evidence of an organic brain impairment during sentencing, I believe the only conclusion is that Fautenberry could establish prejudice in his counsel’s defective performance.
III. CONCLUSION
Given Fautenberry’s history of physical abuse, headaches, and significant head injuries, his counsel had an obligation to investigate fully a potential mitigation defense of an organic brain defect. This obligation did not diminish just because Fautenberry erected obstacles to his attorneys’ efforts. Had Fautenberry’s attorneys scrutinized the basis of their purported expert witness’s conclusion, they would have realized that they had not fully investigated the presence of brain damage as they were obligated to do. Instead, counsel were unaware of the limits of their witness’s testimony and repeatedly emphasized to the sentencing panel that their client had no mental deficiencies. This was both defective and prejudicial. Accordingly, I conclude that Fautenberry has established ineffective assistance of counsel at the mitigation phase of his trial and that the Ohio Court of Appeals’s holding was contrary to clearly established federal law. Therefore, I respectfully dissent.
. The Supreme Court "long ha[s] referred [to these ABA Standards] as guides to determining what is reasonable.” Rompilla, 545 U.S. at 387, 125 S.Ct. 2456 (second alteration in original) (internal quotation marks omitted) (quoting Wiggins v. Smith, 539 U.S. 510, 523, 123 S.Ct. 2527, 156 L.Ed.2d 471 (2003)). "Considering counsel's performance in light of the current ABA Guidelines is proper despite the fact that the ABA Guidelines were issued well after Petitioner's trial, as the ABA Guidelines represent 'a codification of longstanding, common-sense principles of representation understood by diligent, competent counsel in death penalty cases.’" Haliym, 492 F.3d at 717 n. 28 (quoting Hamblin v. Mitchell, 354 F.3d 482, 487 (6th Cir.2003)).
. Even where there are red flags and counsel failed to investigate, we have declined to find ineffective assistance of counsel if the petitioner is unable, even during post-conviction proceedings, to produce any evidence of an organic brain defect. See Morales, 507 F.3d at 939; Carter v. Mitchell, 443 F.3d 517, 529 (6th Cir.2006), cert. denied, - U.S. -, 127 S.Ct. 955, 166 L.Ed.2d 730 (2007). The case at hand, however, is not such a situation where the petitioner has failed to provide medical evidence.