KAREN NELSON MOORE, Circuit Judge.

This case is before us for the second time, following our certification to the Supreme Court of Ohio of the following question of Ohio law: "Does OHIO REV. CODE ANN. § 2743.02(A)(1) require waiver of a party's federal causes of action against state officers or employees when that party files suit in the Ohio Court of Claims based on the same act or omission?" Wrinn v. Johnson, No. 07-4354, slip op. at 11 (6th Cir. Nov. 12, 2008) (unpublished order). On January 28, 2009, the Supreme Court of Ohio dismissed the certified proceeding for lack of prosecution by Plaintiff-Appellant Eugene Wrinn, Jr. ("Wrinn"). In the absence of guidance from the state court, we proceed to apply this court's precedents in Leaman v. Ohio Dep't of Mental Retardation Development Disabilities, 825 F.2d 946 (6th Cir. 1987) (en banc), cert. denied, 487 U.S. 1204, 108 S.Ct. 2844, 101 L.Ed.2d 882 (1988), and Thomson v. Harmony, 65 F.3d 1314 (6th Cir. 1995), cert. denied, 517 U.S. 1105, 116 S.Ct. 1321, 134 L.Ed.2d 473 (1996), which have answered the above question in the affirmative. Accordingly, we AFFIRM the district court's dismissal of all of Wrinn's claims against Defendants-Appellees, three officers of the Ohio State Highway Patrol (collectively, "the OSHP officers").

The background of this case is fully set forth in our order of certification, see Wrinn, No. 07-4354, slip op. at 3-6, and we restate the relevant factual and procedural background only briefly here. Wrinn filed this lawsuit in district court on September 11, 2006, naming three groups of defendants, including the OSHP officers, and asserting six claims under 42 U.S.C. § 1983 and two state-law claims. Wrinn then filed a separate action in the Ohio Court of Claims, naming the State of Ohio and two of the OSHP officers as defendants and asserting four claims under Ohio law arising from the same set of facts alleged in Wrinn's federal complaint. The Ohio Court of Claims subsequently dismissed the two OSHP officers from the case and substituted the Ohio State Highway Patrol ("OSHP") for the State of Ohio as the named defendant. That state suit was stayed pending resolution of this federal-court action.

On October 6, 2006, the OSHP (appearing as an interested party) filed a motion to dismiss the OSHP officers from the federal action under FED. R. CIV. P. 12(b)(6), arguing that Wrinn's claims against the OSHP officers in federal court-were barred under the waiver provision of OHIO REV. CODE ANN. § 2743.02(A)(1) because Wrinn brought suit in the Court of Claims based on the same conduct. On August 13, 2007, the district court granted the OSHP's motion, dismissing both Wrinn's state and federal claims against the OSHP officers. The district court found that it was bound by Leaman v. Ohio Dep't of Mental Retardation Development Disabilities, 825 F.2d 946 (6th Cir. 1987) (en banc), cert. denied, 487 U.S. 1204, 108 S.Ct. 2844, 101 L.Ed.2d 882 (1988), and subsequent decisions of this court holding that § 2743.02(A)(1) requires "a complete waiver of all claims, including federal claims, upon the filing of a similar complaint in the Ohio Court of Claims." Joint Appendix ("J.A.") at 31 (Mem. Op. at 6). On September 20, 2007, the district court granted Wrinn's motion to pursue an immediate appeal under FED. R. CIV. P. 54(b) and stayed further proceedings in the district court pending appeal. Wrinn timely appealed, and on January 22, 2008 filed a petition for initial hearing en banc, which was denied on April 11, 2008.

On appeal, Wrinn argued that the district court erred in ruling that our decision in Leaman controlled to bar Wrinn's claims in federal court against the OSHP officers under the waiver provision of OHIO REV. CODE ANN. § 2743.02(A)(1). In Leaman, we held that § 2743.02(A)(1) barred a plaintiffs federal, as well as state, causes of action against state officials when the plaintiff files suit against the state in the Court of Claims based on the same acts or omissions. Subsequently, the Supreme Court of Ohio decided Conley v. Shearer, 64 Ohio St.3d 284, 595 N.E.2d 862 (1992), which suggested that § 2743.02(A)(1) might not apply to federal civil-rights claims. But in Thomson v. Harmony, 65 F.3d 1314 (6th Cir. 1995), cert. denied, 517 U.S. 1105, 116 S.Ct. 1321, 134 L.Ed.2d 473 (1996), we held that Conley did not speak to the question of whether § 2743.02(A)(1) extends to federal claims and therefore Leaman's holding was undisturbed.

On November 12, 2008, we issued an order sua sponte certifying to the Supreme Court of Ohio the question of whether OHIO REV. CODE ANN. § 2743.02(A)(1) requires the waiver of a party's federal causes of action against state officers when that party files suit in the Ohio Court of Claims based on the same act or omission. We noted that "the Supreme Court of Ohio has never directly ruled on the question of whether § 2743.02(A)(1) is applicable to federal claims" and therefore "[o]ur decisions in Leaman and Thomson remain speculation, or Erie guesses, about the meaning of § 2743.02(A)(1)." Wrinn, No. 07-4354, slip op. at 10. We also noted, however, that "[i]f we were to decide the case before us without certifying this question to the Ohio Supreme Court . . . we would be bound by Leaman and Thomson to hold that all of Wrinn's claims against the OSHP officers are barred by § 2743.02(A)(1)." Id.

Our order of certification was filed at the Supreme Court of Ohio on November 13, 2008. Rule XVIII of the Rules of Practice of the Supreme Court of Ohio requires that "[w]ithin 20 days after a certification order is filed with the Supreme Court, each party shall file a memorandum" addressing the certified question. R. of Prac. Sup.Ct. Ohio XVIII, § 6. The OSHP officers timely filed a memorandum before the twenty-day period expired on December 3, 2008. However, Wrinn's attorneys failed to file the required memorandum by the filing deadline, and the OSHP officers moved the Supreme Court of Ohio to dismiss the certified proceeding for failure to prosecute. On January 28, 2009, the Supreme Court of Ohio granted the OSHP officers' motion to dismiss for want of prosecution by Wrinn. Wrinn v. Johnson, No. 2008-2209, 2009 WL 188485 (Ohio Jan. 28, 2009).

Because the Supreme Court of Ohio dismissed the certified proceeding for failure to prosecute, we now proceed to decide the merits of Wrinn's appeal. As we stated in our order of certification, our decisions in Leaman and Thomson hold that "a plaintiff waives all claims he may have against state officers, including federal claims, when he brings suit in the Court of Claims based on the same acts or omissions." Wrinn, No. 07-4354, slip op. at 10; see also Plinton v. County of Summit, 540 F.3d 459, 463 (6th Cir. 2008) ("The Sixth Circuit has consistently applied Leaman to bar plaintiffs from bringing suit in federal court against a state employee after bringing suit against the state in the Court of Claims based on the same claim."). Because Wrinn brought suit against the State of Ohio in the Court of Claims, OHIO REV. CODE ANN. § 2743.02(A)(1) bars Wrinn's claims in federal court against the OSHP officers based on the same acts or omissions.

CONCLUSION

For the foregoing reasons, we AFFIRM the district court's judgment dismissing all of Wrinn's claims against the OSHP officers.