PRESCRIPTIVE APPROACHES TO COMMUNICATING THE RISK OF VIOLENCE IN ACTUARIAL RISK ASSESSMENT

The logical import of base rates is known among violence risk assessment researchers, but there has been little epistemological discussion of base rates, including identification of the relevant base rate and determining from whence the relevant base rate ought to come. This article describes the substantive considerations before examining whether it is within the purview of expert witnesses to amalgamate the various components into a finalistic risk estimate. Based on existing commentary about the appropriate scope of mental health expert testimony, three approaches to communicating actuarial risk estimates are described and appraised. These approaches are as follows: describing risk factors and their relation to violence; describing the risk of an individual; and describing the risk of an individual in categorical terms. Ultimately, the most appropriate form to communicate actuarial estimates depends on the proper scope of expert testimony, the issue to be addressed, and to some degree the context in which such testimony is proffered.