What is the key legal obligation established by the Tarasoff case?

The key legal obligation established by the Tarasoff case is the duty to warn. This landmark ruling emphasizes that mental health professionals have a responsibility to take action when a credible threat of harm to an identifiable victim is made. In the case, a therapist learned that a patient posed a threat to another individual but did not warn the potential victim, which resulted in a tragic outcome. The court ruled that the therapist had a duty to warn the victim, thereby establishing a precedent for the balance between client confidentiality and the need to protect individuals from foreseeable harm. This ruling reinforces the ethical responsibility of mental health professionals to prioritize safety when a potential threat is identified.