On Friday April 8th, we will have a joint LogiCIC/LIRa session with Elias Tsakas.
Everyone is cordially invited!
Speaker: Elias Tsakas (Maastricht University)
Date and Time: Friday, April 8th 2016, 13:00-14:30
Venue: ILLC Seminar Room F1.15, Science Park 107
Title: Reasonable doubt revisited.
Abstract. According to the common definition, the standard of reasonable doubt is a threshold such that, the defendant is convicted if and only if the probability that the juror attaches to the defendant being guilty is above this threshold. In this paper we prove that generically such a threshold exists if and only if the juror reasons only about the defendant’s guilt and nothing else. We discuss the implications of this result, and subsequently we propose a weakening of the aforementioned definition, by substituting the standard of reasonable doubt with a pair of standards, an upper and a lower one, thus obtaining a sufficient condition for conviction and a sufficient condition for acquittal. Finally, we prove that the lower standard always exists, whereas the upper standard exists if and only if the juror prefers to always convict a guilty defendant, irrespective of the circumstances.