Is retrograde extrapolation admissible in a motor vehicle accident?

As for the cases cited by defendant from other states, these opinions found evidence of retrograde extrapolation is generally reliable and admissible, but faulted the failure of the experts in those cases to set forth the foundational basis for their opinions. None of these cases held the expert must know the individual's particularized burn-off rate. For example, in United States v. DuBois (8th Cir. 1981) 645 F.2d 642, the court held the expert's testimony on retrograde extrapolation was speculative because the defendant had consumed an unknown amount of alcohol between the time he was driving, and when he was taken into custody and given a breath test. (Id. at p. 645.) In so holding, however, the court acknowledged the reliability and admissibility of expert testimony about retrograde extrapolation under the appropriate circumstances:

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