The opinion of the court was delivered by: CONLON
SUZANNE B. CONLON, UNITED STATES DISTRICT JUDGE
Isaac Johnson was tried and convicted of murder and unlawful restraint in the Circuit Court of Cook County. The conviction rested on a number of items of circumstantial evidence linking him to the victim at the place and time of the murder. In addition, the prosecution introduced police testimony that Johnson orally confessed to the crime after a witness identified him in a lineup as the man whom he saw with the victim shortly before her death. Although Johnson's counsel hinted during opening arguments that the statements were not freely and voluntarily made, Johnson introduced no evidence at trial to show that the confession was coerced. Instead, he maintained throughout the trial that he never gave police any statement at all. The focus of the defense therefore centered on the veracity of the police officer who took the oral confession rather than use of force against Johnson.
Defendants present two arguments in their summary judgment motion. First, they renew their contention that Johnson's conviction precludes him from relitigating the voluntariness of his confession in a civil rights damage action. This time they maintain the complaint is barred not only by principles of issue preclusion, or collateral estoppel as it is sometimes referred to, but also by claim preclusion, or res judicata in the narrow sense. They further assert that the complaint is really a thinly veiled attempt to challenge the validity of Johnson's conviction that must be brought by way of habeas corpus, not Section 1983.
It is now well established that the defenses of issue and claim preclusion may be asserted in a civil rights action under 42 U.S.C. § 1983. Allen v. McCurry, 449 U.S. 90, 66 L. Ed. 2d 308, 101 S. Ct. 411 (1980); Farmer v. Lane, 864 F.2d 473, 476 (7th Cir. 1988). It is equally well settled that the law which governs the preclusive effect a state court judgment will have in a Section 1983 case is, as 28 U.S.C. § 1738 mandates, the law of the state that rendered the judgment. Migra v. Warren City School Dist. Bd. of Ed., 465 U.S. 75, 81, 79 L. Ed. 2d 56, 104 S. Ct. 892 (1984); Haring v. Prosise, 462 U.S. 306, 313, 76 L. Ed. 2d 595, 103 S. Ct. 2368 (1983); LaSalle Nat'l Bank v. County of DuPage, 856 F.2d 925, 930 (7th Cir. 1988). The court therefore must look to the Illinois law of issue and claim preclusion to determine what preclusive effect it must give to Johnson's conviction.
Defendants argue that concepts of claim preclusion bar Johnson's excessive use of force claim against them. In Illinois, "the doctrine of res judicata provides that a final judgment on the merits rendered by a court of competent jurisdiction bars any future actions between the same parties or their privies on the same cause of action." Suttles v. Vogel, 126 Ill. 2d 186, 195, 127 Ill. Dec. 819, 533 N.E.2d 901 (1988) (emphasis in original); see also LaSalle Nat'l Bank, 856 F.2d at 931. Defendants clearly have no grounds for applying the rule in this case. This civil rights damage action obviously does not involve the same cause of action as Johnson's criminal proceeding. Furthermore, the identity of the parties required for claim preclusion is not present in this suit.
The federal courts have had some difficulty in deciphering Illinois law governing what constitutes a cause of action for purposes of applying res judicata. See LaSalle Nat'l Bank, 856 F.2d 931-33; Hagee v. City of Evanston, 729 F.2d 510, 512-13 (7th Cir. 1984). As Judge Flaum noted in Hagee, the cases can be analyzed under either the "proof" approach or the "transactional" approach. Id. at 513. Under the "proof" approach, the identity of causes of action is dependent on whether the same evidence would sustain both actions. The evidence needed to sustain Johnson's conviction manifestly is not the same as that necessary to prove the civil excessive use of force claims raised in this case. Under the "transactional" approach, the identity of causes of action turns on whether they arise from a common core of facts. Here again there is no identity of causes of action. The facts relevant to Johnson's conviction concerned the commission of the crimes for which he was convicted, not what transpired in the police station after Johnson's arrest. Absent any identity between the causes of action, defendants cannot use claim preclusion to bar Johnson's suit against the police.
Claim preclusion in Illinois also requires an identity of the parties. There is no mutuality between the parties in this case. The State as prosecutor in Johnson's criminal proceeding cannot be considered to be in privity with the City of Chicago police officers who are defendants in this Section 1983 action. Cf. City of Naperville v. Morgan, 126 Ill. App. 3d 91, 93, 466 N.E.2d 1349, 1350-51, 81 Ill. Dec. 547 (1984). Defendants' argument that Illinois rules of claim preclusion bar this action therefore is unavailing.
Defendants also renew the defense of issue preclusion, even though Judge Leinenweber already rejected it in an earlier order in this case. Judge Leinenweber's decision is now the law of this case and cannot be revisited absent clear and convincing reasons to do so. See United States v. City of Chicago, 853 F.2d 572, 576 (7th Cir. 1988). Defendants' reasons for having this court overrule Judge Leineweber's rebuff of their issue preclusion defense are untenable.
Judge Leinenweber gave two grounds for his decision that Johnson's conviction did not bar his civil rights claim against the police who allegedly beat him in the police station. Citing Brown v. Green, 738 F.2d 202, 206 (7th Cir. 1984), he applied the Illinois rule that "facts underlying a criminal conviction are not given preclusive effect in a subsequent civil action." He further noted that issue preclusion could not bar Johnson's excessive use of force claim because the issue was never actually litigated in the criminal proceedings. Johnson did not raise the issue of a ...