When determining in criminal proceedings whether an individual performed a certain culpable action, predictive evidence is often ignored. Most apparently, and with only few exceptions, base-rates are excluded. Using such evidence in court also seems intuitively inappropriate. For example, using the high rate of crimes involving illegal firearms in a certain neighbourhood to support the conviction of an individual resident in a crime involving an illegal firearm (henceforth, the “crime-rates scenario”) seems highly objectionable. The objection to base-rates is not only aimed at the sufficiency of such evidence (on the grounds that "crime-rates are insufficient on their own to prove that the individual is guilty"). The objection also requires that such evidence should not be used at all in determining the individual’s guilt: that crime-rates should be inadmissible in criminal proceedings. The hostility of criminal fact-finding toward predictive evidence is also apparent in the deeply-rooted suspicion of bad character and previous convictions.
I seek to propose an account, which is admittedly both counterintuitive and demanding in its metaphysical commitments, yet successfully provides a unifying justification for why different types of predictive evidence should not be admitted in criminal fact-finding. I would suggest that the fact-finding practices used to determine culpability in criminal proceedings implicitly adhere to the view that culpable conduct requires free will that is necessarily unpredictable. While theorists of free will disagree on when an action can be considered free, they tend to agree that it is possible to predict a free action, at least to some degree of confidence. Contrary to this dominant view, in this paper I suggest that criminal fact-finding adheres to a theory of free will that includes a necessary condition of unpredictability, according to which free actions cannot have either subjective or objective probabilities. This condition means that an accurate assessment of what an agent is likely to do freely is not merely epistemically unfeasible but metaphysically impossible. It is not only the lack of sufficient information that prevents an accurate prediction of how an agent will act freely: free actions cannot be predicted because their probability does not exist. While I tend to think that, if free will exists, it is necessarily unpredictable, I do not pursue this claim here. Nor do I claim that the unpredictability condition is formally or consciously adopted by any existing legislation or judgment. I only argue that this condition is able to provide the sought-after justification for excluding predictive evidence.
Dr Amit Pundik is Senior Lecturer at Tel Aviv University.