The Sixth Circuit today upheld a trial judge's decision to exclude the defendant's fMRI lie detection evidence in United States v. Semrau, No. 11-5396.
Due to the recognized lack of real world testing, this same laboratory/real world distinction applies to the other facet of the third factor, the existence and maintenance of standards, as well as the fourth factor, general acceptance. There was simply no formal research presented at the Daubert hearing demonstrating how the brain might respond to fMRI lie detection testing examining potential deception about real world, long-term conduct occurring several years before testing in which the subject faces extremely dire consequences (such as a prison sentence) if his answers are not believed. See Fed. R. Evid. 702(c) (requiring expert testimony to be the "product of reliable principles and methods").