The objective of this paper is to address the empirical basis and forensic application of a bimodal theory of violence. The definitions of affective and predatory violence, the relevant animal and clinical research, and the current empirical evidence in neurochemistry, neuropsychology and psychophysiology are reviewed. Forensic evidence for the relevance of this bimodal theory is investigated. An appropriate methodology for data gathering, and two observational measures along with one self-report measure are explicated. Integration of this bimodal theory into forensic practice is suggested. Affective and predatory modes of violence represent an empirically valid bimodal theory of violence, find application in forensic psychiatry, and scientifically deepen the understanding of discrete violent acts for both retrospective and prospective psychiatric and psychological investigations. This bimodal theory of violence should have a place in forensic psychiatric practice.