This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Law and Human Behavior, Vol. 27, No. 6, December 2003 ( C  2003) Toward an Empirical Approach to Evidentiary Ruling Deborah Davis 1,2 and William C. Follette 1 This paper responds to criticisms/misconstruals of our measure of the maximum proba- tive value of evidence (D. Davis & W. C. Follette, 2002), and our conclusions regarding the potentially prejudicial role of “intuitive profiling” evidence, including motive. We argue that R. D. Friedman and R. C. Park’s (2003) criticisms and example cases are largely based on inappropriate violation of the presumption of innocence. Further, we address the merits of our absolute difference measure of probative value versus those of the Bayesian likelihood ratio championed by D. H. Kaye and J. J. Koehler (2003). We recommend methods for presentation of measures of evidence utility that convey complexities of interdependence between new and existing evidence. Finally, we propose a “probable cause” standard for admission of potentially prejudicial ev- idence, dictating that admissibility of such evidence should be contingent upon other substantial evidence of guilt. KEY WORDS: evidence; probative value; motive; utility; profiling; empirical. Participants in this exchange are among a growing number of social science and legal scholars who advocate probabilistic approaches to evaluation of evidence. Notwith- standing the existence of differences in specific approach among the participants, there exist fundamental areas of agreement that underscore the value of statistical approaches to assessing the utility of evidence. Hence, after some initial commentary on the crucial issue of the presumption of innocence and some broad misconstruals of our approach by our critics, we examine these areas of agreement. Following this, we state our position regarding how to construct and present indices of evidence utility, and in this context we explore areas of disagreement between our approach and those of our critics. Although our original paper and those of our critics have devoted considerable attention to the Franklin case and other evidentiary issues specifically involving ux- oricide, this paper will focus on broader issues of evidence utility. Our analysis of the Franklin case was based upon the specific assignment we were given—namely, to determine whether unfaithful men were more likely to murder their wives—and 1 Department of Psychology, University of Nevada, Reno, Nevada. 2 To whom correspondence should be addressed at Department of Psychology, University of Nevada, Reno, Nevada 89557; e-mail: debdavis@unr.nevada.edu or follette@unr.edu. 661 0147-7307/03/1200-0661/1 C  2003 American Psychology-Law Society/Division 41 of the American Psychology Association