Tarasoff in Missouri: The jurisprudence of a mental health provider's duty to warn and protect non-patients of potential risks from patients.

In 1976, the Supreme Court of California issued its well-known Tarasoff Principle. From this principle, other courts found a duty to warn, and some found more than just a duty to warn, a duty to protect. As courts in other states adopted a version of the Tarasoff Principle, they issued a wide variety of third-party liability rules. In light of the dynamic, everchanging Tarasoff jurisprudence in the United States and recent relevant appellate court opinion in Missouri, a timely updated summary and update of Tarasoff-related jurisprudence in Missouri is warranted. In the present analysis, we compiled the four appellate court decisions that pertained to the questions of Tarasoff-like third-party liability in the State of Missouri: Sherrill v. Wilson (1983), Matt v. Burrell (1995), Bradley v. Ray (1995), and Virgin v. Hopewell (2001). We reviewed all legal measures for clinicians to protect nonpatients in Missouri, not just those that relate to protecting nonpatients from violence as in a Tarasof-like scenario. Thus, this paper concisely provides a compendium of such options and allows for a meaningful comparison of which legal, protective measures are mandatory and which are permissive, thereby evoking the question of whether measures of protecting nonpatients from a patient's violent acts ought to be mandatory duties or permissive application of professional judgment.