In State v. Alexander, 214 Wis. 2d 628, 571 N.W.2d 662 (Wis. 1997), the defendant was accused of operating a motor vehicle with a prohibited alcohol concentration.
Because of his prior record the defendant was charged with an aggravated version of the crime, similar to the felony driving under the influence offense in Florida.
One of the offense's elements was that the defendant must have two or more prior convictions, suspensions, or revocations as counted under statute. 571 N.W.2d at 664.
Despite the defendant's admission of that element of the crime, the trial court admitted the particulars of the prior offenses into evidence and the defendant was convicted.
The Wisconsin Court of Appeals held that it was error to allow the particulars of the prior convictions into evidence, but found the error harmless.
On review, the Wisconsin Supreme Court relied on Old Chief v. United States, 519 U.S. 172 (1997) in its analysis:
Introducing evidence of the defendant's prior convictions . . . served no purpose other than to prove the status element of the charged offense. Admitting this evidence to prove this status element, and submitting the status element to the jury adds nothing to the State's evidentiary depth or descriptive narrative. It does nothing to fulfill a juror's expectations. This evidence and element, does, however, tell a juror that the defendant has had a problem in the past, probably with drinking and driving. It raises an inference that the defendant has a bad character and a propensity to drink and drive, and that is the very result prohibited by the rules of evidence. Id. at 671.
Nevertheless, the court found the error harmless due to the "overwhelming nature" of the evidence supporting the defendant's guilt. Id. at 672.