State v. Andres DelReal, 225 Wis.2d 565, 593 N.W.2d 461 (Ct. App. 1999).
For DelReal: Richard D. Martin, SPD, Milwaukee Appellate.
Holding: At trial on shooting related charges, one detective testified that DelReal’s hands had been swabbed for gunshot residue (with unknown results), but the lead detective testified that he hadn’t. The trial court struck testimony about the swabbing, ruling it irrelevant. Turns out that DelReal was swabbed and, the results were negative for gunshot residue. The court of appeals holds, first, that “(t)his fact [swabbing] is relevant to attacking both [the lead detective’s] credibility and the quality of the police investigation.” Relatedly, the court holds that even if the negative test result “cannot conclusively prove that Delreal was not the shooter because he may have taken some action to eliminate any positive evidence, such as washing his hands to remove any residue,” it is nonetheless relevant because it “reduces the probability that DelReal fired the gun.” Any inconclusiveness goes to weight, not admissibility, the court analogizing to the “similar conclusion on facts analogous to those presented here,” in Kyles v. Whitley, 514 U.S. 419 (1995).
he court seems to premise admissibility on two separate grounds. First, the negative test results had at least some weight, in that it tended to show that DelReal wasn’t the shooter. Surveying case law from other jurisdictions, the court generalizes, “(t)he inconclusive nature of this evidence [residue-testing] does not render it inadmissible, but rather, affects its probative value, which is for the jury to determine.” Second, and as a seemingly separate basis for admissibility, the lead detective’s “credibility was also fair game for defense attack.” Applying the favorable Dyess test, the court rejects harmless error. The case “was by no means airtight.” Eyewitness identifications “were equivocal,” at least initially, and therefore “were not beyond challenge.” The evidence wasn’t “so overwhelming that the State’s failure to disclose this relevant potentially exculpatory evidence was harmless.”