COGNITION, EXPERT TESTIMONY, AND THEORIES OF LEGALLY RELEVANT EVENTS

Expert testimony in human cognition are being used increasingly in legal situations. In this article, I describe how such testimony is formulated and provided. I illustrate using three criminal cases in which expert testimony in cognition was used. For each case I describe how combining the known physical facts surrounding the event in question with known psychological facts about the workings of human cognition can assist in providing for the trier of fact a theory of how the event unfolded. G.R. Loftus Page 3 of 17 10/26/10 In this article I will depart from the normal practice of describing a mostly scientific experimentation, accompanied by a brief description of how the research may be applied to practical settings. Instead, I will reverse this practice: I will describe applications of research in human perception and memory to practical situations in the law with only sporadic reference to the research on which these applications are based. In this way, the scope of potential applications can be described. I will, in particular, focus on three legal cases in which I have been involved as an expert witness in the domain of human participation and memory. I have selected these cases somewhat arbitrarily, but among them, they represent a fairly broad illustration of how principles derived from scientific work i