Schumacher was convicted of OWI with a prohibited alcohol content in connection with an accident at 8:45 p.m. His blood was drawn at 10:56 p.m., and tests showed a BAC of .171, well above his legal limit of 0.08. The sole issue on appeal was whether Schumacher’s trial counsel had adequately cross-examined Kristin Drewieck, a chemist with the Wisconsin State Laboratory of Hygiene about her estimates of Schumacher’s BAC at 8:45 p.m.
Drewieck calculated three different estimates for a 200 pound man depending on whether he drank more alcohol (and if so, the amount) between the time of the accident and the time of the blood draw. Drewick repeatedly acknowledged that her BAC calculations were “just estimates.” They were only as good as the information plugged into the calculations. She also acknowledged that she guessed at a number of the variables she used.
Trial counsel did not press Drewieck about these matters on cross-examination because he thought she might change her testimony. Nor did he ask how the food Schumacher had consumed affected her calculation or about the rate of alcohol elimination. but did ask about how the size and alcohol content of the drinks Schumacher consumed might affect her calculations.
Schumacher argued that trial counsel ineffectively cross-examined Drewieck. The circuit court held that counsel did not perform deficiently, and the court of appeals affirmed. It held that counsel made a strategic decision to not engage in further questioning regarding the reliability of retrograde extrapolation because it might elicit repetitive information that would alienate the jury and give Drewieck a chance to refine her answers. Opinion,¶39. He appropriately focused on variables he thought the jury could understand, as opposed to all questionable variables. In any case, Schumacher failed identify what testimony further cross-examination would have elicited. Opinion, ¶40.