State ex rel. Hughes v. Cuyahoga Cty. (Slip Opinion), 2017 Ohio 7780

In 2000 Hughes was indicted on two aggravated-murder counts (with specifications), one attempted aggravated-murder count, and four weapons counts in Cuyahoga County.
In 2001 Hughes pleaded guilty to two aggravated-murder counts and some specifications under a plea agreement; remaining counts/specifications were dismissed; he was sentenced to two consecutive 30-year terms plus 3 years for a firearm specification.
In March 2015 Hughes filed a motion in his criminal case titled a Crim.R. 32(C) motion seeking revision/correction of the judgment entry and de novo resentencing, presenting six issues for review.
The trial court denied that motion on May 28, 2015; Hughes did not appeal that denial.
In May 2016 Hughes filed a mandamus petition in the court of appeals raising the identical six issues and asking for a new sentencing hearing on the ground that the sentencing entry was void.
The court of appeals dismissed the mandamus petition as barred by res judicata; the Supreme Court of Ohio affirmed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Hughes is entitled to a writ of mandamus ordering a new sentencing hearing because the sentencing entry is void	Hughes argued the sentencing entry was defective and void, entitling him to de novo resentencing	Cuyahoga County argued Hughes’s claims had been presented to and denied by the trial court and therefore are barred by res judicata	Court held claims were barred by res judicata; mandamus denied
Whether res judicata precludes relitigation of claims raised in the trial-court motion	Hughes implicitly contended the mandamus action was a proper vehicle notwithstanding the prior denial	County argued final judgment on the motion (trial-court denial) bars the same claims in a subsequent action between same parties	Court held res judicata (claim preclusion/issue preclusion) applies and bars the petition

Grava v. Parkman Twp., 73 Ohio St.3d 379 (1995) (explaining res judicata encompasses claim and issue preclusion)
Brooks v. Kelly, 144 Ohio St.3d 322 (2015) (a final judgment on the merits by a competent court bars subsequent actions on the same claim)