"Both culpability and dangerousness are exceedingly difficult to gauge; even mental health professionals well-versed in the behavioral sciences cannot claim a high degree of reliability in their efforts to address these issues. Though the current trend in evidence law is to demand a rigorous demonstration of scientific validity from expert witnesses, especially when those experts are mental health professionals are proffered by the defense, this book argues that this is a mistake. Such a position undermines the fairness of the process and could quite possibly even diminish its reliability, given the defense's constitutional entitlement to tell its story and the inscrutability of past and future mental states. At the same time, Professor Slobogin proposes a number of ways the courts can ensure that experts provide the best possible information about ultimately unknowable past mental states and future behavior."--Jacket.