The traditional approaches to dangerous persons are crime and commitment. The criminal law punishes responsible actors, and the civil law confines the mentally ill. These approaches leave a gap: the state cannot substantially restrict the liberty of responsible actors until they have committed a crime. In response to this gap, the criminal law’s boundaries have expanded to include preparatory offenses and early inchoate conduct that deserve only minimal punishment, if any, reflecting states’ attempts to incarcerate the dangerous. Meanwhile, the Supreme Court’s effort to articulate a test of mental disease warranting involuntary confinement of sexual predators has failed to draw a principled distinction between the ordinary criminal and the mentally ill.
This Article asserts that rather than contorting the criminal or commitment models, there is a theoretical justification for substantial liberty deprivations of responsible, but dangerous, actors. Drawing on the concept of “liability to defensive force” from the self-defense literature, this Article argues that just as a culpable attacker’s own conduct grounds a defender’s right to response, a dangerous actor who begins a course of criminal conduct grounds the state’s right to stop him. This Article articulates what conduct is sufficient for “liability to preventive interference” as well as what the forms of preventive interference could be. In addition, this new form of liability is assessed in terms of constitutional implications, the civil-criminal divide, and practical considerations.