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Retrograde extrapolation survives Daubert challenge—again

State v. Michael Chough, 2016AP406-CR, District 2, 1/25/17 (one-judge decision; ineligible for publication); case activity (including briefs)

Chough’s challenge to the reliability of expert testimony regarding his blood alcohol content at the time he was driving fails under State v. Giese, 2014 WI App 92, 356 Wis. 2d 796, 854 N.W.2d 687.

¶20     We see no problem in the court’s summary rejection of Chough’s intimations that retrograde extrapolation is “junk science.” The method is well- established in our courts. See Giese, 356 Wis. 2d 796, ¶22 (explaining that “retrograde extrapolation is a generally accepted scientific method” and “[w]e are not aware of any court that has determined that the general methodology of … retrograde extrapolation fails the Daubert standard”). Of course, retrograde extrapolation is subject to “certain doubts and disagreements.” Giese, 356 Wis. 2d 796, ¶23. But “[t]he mere fact that some experts may disagree about the reliability of retrograde extrapolation does not mean that testimony about retrograde extrapolation violates the Daubert standard.” Giese, 356 Wis. 2d 796, ¶23. We think the established history of retrograde extrapolation—revealed in appellate decisions and the circuit court’s experience—was fair game for the court to rely on. ….

¶21     Furthermore, Chough’s objections are not new. They very closely mirror the arguments in Giese that retrograde extrapolation analysis could not be performed because the time of driving was unknown…. Giese, 356 Wis. 2d 796, ¶9. The defendant in Giese even cited the same expert—Kurt Dubowski—for the proposition that “no forensically valid forward or backward extrapolation … is ordinarily possible in a given subject … solely on the basis of time and individual analysis results.” Id., ¶10…. We rejected those arguments and held that “Giese’s questions go to the weight of the evidence, not to its admissibility.” Id., ¶28….

Chough also claimed police lacked probable cause to arrest him because, even though there was reason to believe Chough was intoxicated, the officer found him some time after he was driving and had an accident, and therefore didn’t have a basis to conclude he was intoxicated when he was driving:

¶15     Chough was found a mere quarter-mile from the accident exactly as the [dispatch] reports indicated: looking for shelter in a trailer court. Chough even admitted to police that he had been driving the car and offered the explanation that he fell asleep at the wheel. It is true that Chough did not tell [Deputy] Klinkhammer exactly when he had been driving, but—as the circuit court observed—common sense dictates that the accident was recent. The vehicle had not been towed away at that point, and Klinkhammer observed Chough soon after hearing reports of a man looking for shelter. Nothing indicates that Chough sat in the crashed vehicle or wandered around for hours after the crash. Nor is it plausible that Chough stopped for a drink between crashing his car and seeking shelter and became intoxicated after the accident. Furthermore, Chough’s refusal to cooperate with the sobriety tests is indicative—though certainly not dispositive—of his consciousness of guilt. And, it is worth stating again, Chough admitted he had been driving the crashed vehicle. A reasonable law enforcement officer would, as Klinkhammer did, believe Chough had been driving while intoxicated. ….

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