The state of Florida appeals the district court’s grant of habeas corpus. Because the district court correctly determined that petitioner Stephen Todd Booker’s death sentence was imposed in violation of Hitchcock v. Dugger, 481 U.S. 393, 107 S.Ct. 1821, 95 L.Ed.2d 347 (1987) (applying Lockett v. Ohio, 438 U.S. 586, 98 S.Ct. 2954, 57 *634L.Ed.2d 973 (1978), to Florida capital punishment process), and because this error was not harmless, we affirm.
The facts of the underlying crime are set out in the opinion of the Florida Supreme Court on direct appeal. Booker v. State, 397 So.2d 910 (Fla.), cert. denied, 454 U.S. 957, 102 S.Ct. 493, 70 L.Ed.2d 261 (1981).
Booker’s claim for relief is that the court that sentenced him to death was precluded from considering nonstatutory mitigating evidence he presented. Hitchcock, 481 U.S. at 393, 107 S.Ct. at 1821. Although Booker has been through one round of habeas corpus consideration in the federal courts, see Booker v. Wainwright, 703 F.2d 1251 (11th Cir.), cert. denied, 464 U.S. 922, 104 S.Ct. 290, 78 L.Ed.2d 266 (1983), his claim is not procedurally barred because Hitchcock represents a significant change in the law since his previous petition. Messer v. Florida, 834 F.2d 890, 892-93 (11th Cir.1987). He has exhausted his state court remedies. Booker v. Dugger, 520 So.2d 246 (Fla.), cert. denied, 486 U.S. 1061, 108 S.Ct. 2834, 100 L.Ed.2d 935 (1988).
Both the Florida Supreme Court and the district court found that there had been Hitchcock error at Booker’s trial. The jury instruction given by the trial judge was the equivalent of that given in Hitchcock, and the prosecutor told the jury that they were only to consider the listed statutory mitigating circumstances. Booker v. Dugger, 520 So.2d at 247; District Court Order, Sept. 19, 1988, at 2. In a presentence memorandum, Booker’s counsel brought the then-recent decision in Lockett, 438 U.S. at 586, 98 S.Ct. at 2954, to the trial court’s attention. See “Memorandum in Support of Motion to Exclude the Death Penalty,” Record on Appeal to Florida Supreme Court, pp. 135-37. However, Lock-ett did not figure in counsels’ arguments to the court at the presentence hearing nor in the court’s sentencing decision. Although the trial court, in passing sentence, noted that it “carefully considered” all the evidence in aggravation and mitigation introduced at trial, it then only discussed mitigating evidence as it applied to the statutory factors. See “Judgment and Sentence,” Oct. 20, 1978, Record on Appeal, Tab C, p. 29.
The Florida Supreme Court held that the Hitchcock error was harmless, noting that “[tjhere was simply no nonstatutory mitigating evidence sufficient to offset the aggravating circumstances upon which the jury could have reasonably predicated [a recommendation of life].” Booker v. Dugger, 520 So.2d at 249. That court also postulated that the sentencing judge would have overridden any jury recommendation of a sentence less than death. Id. The district court found that neither the sentencing jury nor the judge considered Booker’s nonstatutory mitigating evidence outside of the statutory scheme. Because it was loath to speculate as to the possible effects of this excluded evidence on the sentencing body, the district court granted the writ. Order, p. 3.
Our analysis is focused solely on Florida’s contention that the Hitchcock error was harmless beyond a reasonable doubt. See generally Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 828, 17 L.Ed.2d 705 (1967). This court’s precedents have largely limited the applicability of harmless error analysis in Hitchcock claims to instances where the petitioner or counsel made a strategic decision not to present mitigating evidence, or where no nonstat-utory mitigating evidence could have been produced. See, e.g., Delap v. Dugger, 890 F.2d 285, 304-06 (11th Cir.1989) (error not harmless where evidence of remorse, capacity for rehabilitation, good behavior, and organic brain damage not considered), cert. denied, — U.S.-, 110 S.Ct. 2628, 110 L.Ed.2d 648 (1990); Demps v. Dugger, 874 F.2d 1385, 1389-91 (11th Cir.1989) (error harmless where record revealed the nonavailability of supportable mitigating evidence), cert. denied, — U.S. -, 110 S.Ct. 1834, 108 L.Ed.2d 963 (1990); Tafero v. Dugger, 873 F.2d 249, 252 & nn. 4-5 (11th Cir.1989) (per curiam) (error harmless where no significant nonstatutory mitigating evidence existed and where counsel purposely presented no nonstatutory mitigating evidence), cert. denied, — U.S. -, 110 S.Ct. 1834, 108 L.Ed.2d 962 *635(1990); Jones v. Dugger, 867 F.2d 1277, 1279-80 (11th Cir.1989) (error not harmless where evidence of prison rehabilitation not considered); Clark v. Dugger, 834 F.2d 1561, 1569-70 (11th Cir.1987) (error harmless where trial counsel made strategic decision not to introduce any mitigating evidence), cert. denied, 485 U.S. 982, 108 S.Ct. 1282, 99 L.Ed.2d 493 (1988); Magill v. Dugger, 824 F.2d 879, 893-95 (11th Cir.1987) (error not harmless where evidence of remorse excluded).
From these decisions, a Hitchcock error will not be found harmless if the evidence excluded from the jury’s sentencing deliberations by a limiting instruction could have had any effect on the jury’s recommendation. See Skipper v. South Carolina, 476 U.S. 1, 8, 106 S.Ct. 1669, 1673, 90 L.Ed.2d 1 (1986) (Lockett violation not harmless because Court could not “confidently conclude” that the excluded evidence “would have had no effect upon the jury’s deliberations”). In situations where counsel has made a strategic choice not to introduce any mitigating evidence, it is clear that Hitchcock violations are harmless: "Having failed to produce evidence of any nonstatutory mitigating factors, [petitioner] can hardly complain that the trial court restricted the jury’s ability to consider them.” Clark, 834 F.2d at 1570. Likewise, where no true mitigating evidence exists, Hitchcock is not implicated. See, e.g., Demps, 874 F.2d at 1396 (Clark, J., specially concurring) (“Where there is no nonstatutory mitigating evidence there can be no Hitchcock error and harmlessness need not be considered.”).
In petitioner’s case it is clear beyond cavil that significant nonstatutory mitigating factors were excluded from the jury’s consideration by the erroneous jury charge. Booker was the only defense witness at the sentencing phase of the trial, and he testified that he had been hospitalized for psychiatric reasons nine times beginning at age 13, that he had severe problems with alcohol and drugs and had experienced blackouts, and that he was honorably discharged from the Army. He said he could not remember the crime, but that if he did it he felt remorseful. He also stated, against counsel’s advice, that someone who had committed this type of crime should receive the death penalty. Although no psychiatric testimony was presented during sentencing, Booker did call one psychiatrist during the guilt phase of his trial; the testimony adduced showed that, although Booker was not insane, his records from Walter Reed Army Medical Center indicated that Booker suffered from an organic brain disorder as a result of drug use. The psychiatrist also testified that there were indications of paranoid schizophrenia. The police officer who took Booker’s confession testified that Booker seemed to have a split personality when he confessed. Booker assumed the identity of “Aniel”; he said that “Steve” committed the murder; he clenched his teeth so hard they cracked; and he laughed and cried uncontrollably. The officer stated that he did not think Booker was faking.1 There was also evidence that Booker was cooperative with the police, and that he may have made the anonymous phone call reporting the murder.
After the jury recommended death by a 9-to-3 vote, the trial judge was presented with other evidence prior to passing sentence. This evidence included the report of a court-appointed psychiatrist. This report concluded that Booker had above normal intelligence but was impulsive and had difficulty postponing gratification. It also noted that Booker had had little supervision as a child, that he began drinking and using drugs as a teenager, and that he had experienced hallucinations. The psychiatrist concluded that Booker was not under extreme emotional duress or the domination of another at the time of the crime. But due in part to intoxicants he had consumed, Booker was “most probably ... less able than the average individual to conform his conduct to the requirements of the law.”
The Delap case presents very similar circumstances. Both Delap and Booker expressed remorse for their crimes and coop*636erated with the authorities. Delap, 890 F.2d at 306. More significantly, there was considerable evidence that Delap, like Booker, suffered from an organic brain disorder. Id. In Delap, this court noted that “[t]here was substantial and significant psychological evidence which the jury, if it followed the court’s instruction, would have considered only if it rose to the level of a statutory mitigating factor; i.e., only if the jury found that Delap committed the crime ‘under the influence of extreme mental or emotional disturbance.’ Fla.Stat. § 921.141(6)(b) (1977) (emphasis added)_ Had the jury been properly instructed, it may have considered the psychological evidence in mitigation even if it did not find that the evidence met the required threshold level for a statutory mitigating factor.” Delap, 890 F.2d at 305-06. Comparably, Booker’s jury may have found that his psychiatric nonstatutory mitigating evidence did not rise to the level of the Florida statutory mitigating circumstances.2 The Delap court also found significant the fact that at least one juror voted for life imprisonment, id. at 306, whereas three of Booker’s jurors voted for life.
Thus there was available, nonstatutory mitigating evidence that was not considered by the sentencing jury or judge due to the Hitchcock violation.3 Because we are not able to speculate as to the effect this substantial evidence would have had on the sentencing body, we cannot find the error harmless, regardless of the number of aggravating circumstances that may have been found. See Knight, 863 F.2d at 710.4
The state of Florida has not shown the existence of harmless error beyond a reasonable doubt. Accordingly, the order of the district court is AFFIRMED.
. The trial court judge found that this evidence was self-serving.
. Booker’s prosecutor argued that none of the mitigating circumstances, including the "extreme mental or emotional disturbance” factor, applied. The trial judge found no statutory mitigating factors.
. In addition to the evidence that was presented but was not considered, evidence existed that could have been submitted at the sentencing phase if counsel had not believed that the law limited him to statutory mitigating circumstances. See Knight v. Dugger, 863 F.2d 705, 759 (11th Cir.1988) (Clark, J., concurring). The examining psychiatrists could have been called to testify concerning Booker’s mental health history. This history included (1) a brief commitment at the age of 14 because he had choked his dog and hit his mother; (2) treatment at Walter Reed for several months; (3) a seizure while in prison and treatment with Dilantin; (4) hallucinations during childhood; and (5) two suicide attempts in jail following the murder. Other possible nonstatutory mitigating evidence included educational and institutional records showing Booker’s artistic ability, drinking problems, and schizophrenia.
.The state of Florida argues that this court must show deference to the Florida Supreme Court’s determination that the error was harmless. Federal courts are not, however, bound by state court rulings on harmless error. See, e.g., Grizzell v. Wainwright, 692 F.2d 722, 725 (11th Cir.1982), cert. denied, 461 U.S. 948, 103 S.Ct. 2129, 77 L.Ed.2d 1307 (1983).