People’s Expert Was Not Qualified to Testify About “Reverse Extrapolation” in DWI Prosecution/”Reverse Extrapolation” Is an Accepted Theory However
In this DWI prosecution, the Third Department determined the People’s expert was not qualified to offer testimony about “reverse extrapolation,” but that the theory itself was sound:
[We reject defendant’s generalized challenge to] the theory of reverse extrapolation – the process by which an expert, taking into consideration, among other things, an individual’s known BAC at a particular point in time, renders an opinion as to the individual’s BAC at an earlier point in time. Assuming the expert in question is qualified and a proper foundation has been laid for such opinion, reverse extrapolation testimony may be…. Here, however, the People failed to lay a proper factual foundation for [the expert’s] testimony and, therefore, defendant’s objection in this regard should have been sustained. People v Menegan, 105337, 3rd Dept, 6-13-13