Asher was a 32-year-old deputy officer at the Kentucky River Regional Jail when a jury convicted him of deprivation of civil rights and obstruction of justice for his role in (and later cover up of) an unprovoked, vicious assault of a 55-year-old inmate awaiting trial on a misdemeanor charge. The district court imposed a 9-year sentence

Today's decision, written by Judge Bush, concluded that the trial court erred by allowing in testimony that Asher had beaten a prisoner and covered it up 2½ years earlier.

and that it was admissible under Asher conceded that prosecutors had sufficient evidence that the prior assault occurred,that it was admissible under Rule 404(b) to prove that he acted purposefully.

But Asher argued that the evidence wasn't admissible under Rule 403, which provides a balancing test that allows exclusion of relevant evidence if " its probative value is substantially outweighed by the danger of unfair prejudice ."

The Sixth Circuit decided that -- despite deference due to the trial court's evidentiary decisions -- the risk of unfair prejudice from introduction of the prior assault so outweighed its probative value that it constituted reversible error.

The court first addressed probative value, explaining that, if the jury believed Asher committed the vicious assault at issue, then specific intent would have been obvious. "It is specious to think," the court reasoned, "that the jury might have disbelieved Asher's denials, yet acquitted him for lack of specific intent." And as to prejudice, the court found that, because the two assaults were "virtually identical," a curative jury instruction wasn't enough to mitigate the negative inference about Asher's character that would arise from evidence of the prior assault.

The court thus vacated both the conviction and the 9-year sentence, and remanded for a new trial.