In State v. Keggan, 2006-Ohio-6829, the Second District Court of Appeals upheld the conviction of the defendant despite the fact that the Highway Patrol destroyed a videotape which it was ordered to preserve.  Summary by the Court: “Videotape destroyed by law enforcement agency, in violation of an order to preserve it, was not shown to be potentially useful to Defendant, and so whether the agency acted in bad faith is immaterial; conflict in officer’s and Defendant’s testimony was for the trial court to resolve. Affirmed. (J. Fain concurring in the judgment.)”  The defendant was found guilty and the Court of Appeals affirmed.

http://www.sconet.state.oh.us/rod/newpdf/2/2006/2006-ohio-6829.pdf