In Tarasoff v. Regents of the University of California, the California Supreme Court held in 1976 that a mental health professional who determines, or reasonably should determine, that a patient poses a serious danger of violence to another person has a legal duty to take reasonable steps to protect the foreseeable victim. The ruling made public safety a limit on patient confidentiality when a specific, credible threat exists, and it has since shaped mental health law across most of the United States.
What the Case Was About
The lawsuit grew out of the 1969 killing of Tatiana Tarasoff, a student at the University of California, Berkeley. Her killer, Prosenjit Poddar, had told his university psychologist, Dr. Lawrence Moore, that he intended to kill her. Dr. Moore asked campus police to detain Poddar for psychiatric evaluation; they briefly did, then released him after he seemed rational. Dr. Moore’s supervisor directed that no further action be taken and that the clinical notes and the letter to police be destroyed.1Office of Justice Programs. Tarasoff vs the Regents of the University of California et al
No one warned Tatiana Tarasoff or her family. Two months after his release, Poddar went to her home and killed her. Her parents sued the university’s therapists and the campus police for failing to warn.
What the Court Decided
The California Supreme Court ruled for Tarasoff’s parents. The court wrote that “once a therapist does in fact determine, or under applicable professional standards reasonably should have determined, that a patient poses a serious danger of violence to others, he bears a duty to exercise reasonable care to protect the foreseeable victim of that danger.”2Justia. Tarasoff v. Regents of University of California Confidentiality mattered, the court said, but it had to yield when a specific person faced a credible threat of serious violence.
From a Duty to Warn to a Duty to Protect
The court issued two opinions in the case. Its 1974 opinion, often called Tarasoff I, framed the obligation narrowly as a duty to warn the intended victim. After rehearing, the court issued a revised opinion in 1976 (Tarasoff II) that broadened the standard to a duty to protect. That change matters. Warning is only one way to satisfy the obligation; a therapist may also notify police, pursue involuntary commitment, or intensify treatment, depending on what the circumstances reasonably call for.2Justia. Tarasoff v. Regents of University of California
The Dissent
Justice William Clark dissented. He argued that patients who know their disclosures might be reported will either avoid therapy or withhold the very thoughts a therapist needs to hear, leaving no one in a position to intervene. The concern was that a rule meant to prevent violence could end up producing more of it.
When the Duty Is Triggered
Not every angry statement in a session activates the duty. Two elements have to be present together:
- A serious threat of physical violence. The patient must communicate a credible intent to cause serious physical harm, not vague hostility or property damage.
- A reasonably identifiable victim. The threat must be aimed at a specific person or an identifiable group, not the public at large.
A patient who says “I’m so angry I could hurt someone” generally does not trigger the duty, because no specific victim can be identified. A patient who names a person and describes a plan to harm them generally does. The judgment falls on the therapist, measured against what a reasonable professional with similar training would conclude in the same situation.
A small number of states have stretched the trigger beyond threats to people. At least one includes threats to real property, and another extends the duty to threats involving any criminal act. Those are outliers. Most jurisdictions keep the trigger tied to threats of serious physical violence against identifiable individuals.
How a Therapist Can Satisfy the Duty
Because the 1976 opinion framed the obligation as protection rather than warning, therapists have options. Warning the potential victim is one. Notifying law enforcement is another. Seeking hospitalization of the patient, or adjusting the treatment plan to reduce the risk, can also fulfill the duty. What counts is whether the therapist’s response was reasonable given what they knew.
When directly warning the potential victim could increase the danger, a therapist may choose an alternative protective step instead. Documentation of the reasoning behind that choice becomes important. If the decision is later challenged, a court will look for evidence of a thoughtful risk assessment, not just a paper trail of inaction.
Does HIPAA Prevent a Therapist From Warning?
Federal privacy law does not block the kind of disclosure Tarasoff contemplates. Under federal regulations, a covered healthcare provider may disclose protected health information without patient consent when the provider, in good faith, believes the disclosure is necessary to prevent or lessen a serious and imminent threat to health or safety. The disclosure has to go to someone reasonably able to prevent or lessen the threat, which can include the intended victim or law enforcement.3eCFR. 45 CFR 164.512 – Uses and Disclosures for Which an Authorization or Opportunity to Agree or Object Is Not Required
The regulation also carries a good-faith presumption. A provider who acts on actual knowledge of the threat, or on a credible representation from someone with apparent knowledge, is presumed to have acted in good faith. In practical terms, HIPAA runs parallel to state duty-to-protect law rather than in conflict with it.3eCFR. 45 CFR 164.512 – Uses and Disclosures for Which an Authorization or Opportunity to Agree or Object Is Not Required
Immunity for Therapists Who Act in Good Faith
One of the practical worries the ruling created was that therapists could be sued from both sides: by a victim for failing to warn, or by a patient for breaching confidentiality. Most states with a duty to protect have addressed this through immunity provisions that shield therapists who act in good faith to fulfill the duty.
California codified its own protection in Civil Code Section 43.92. Under that statute, a psychotherapist faces no monetary liability for failing to protect unless the patient has communicated a serious threat of physical violence against a reasonably identifiable victim. When a threat has been communicated, the therapist can reach safe harbor by warning the potential victim and notifying law enforcement.4California Legislative Information. California Code, Civil Code – Section 43.92 Other states with duty-to-protect statutes use similar frameworks, though the specific steps required to earn immunity vary.
What Happens If a Therapist Fails to Act
The exposure is civil, not criminal. No therapist has been criminally prosecuted for violating the duty to protect. The claims arise in civil court, brought by the victim or the victim’s family under a negligence or malpractice theory.
The analysis tracks a standard malpractice claim. The plaintiff must show that a duty existed, that the therapist breached it by failing to take reasonable steps, and that the failure was a proximate cause of the harm. Damages can include compensation for physical injuries, emotional harm, lost income, and wrongful death. Where a state has enacted a duty-to-protect statute, the statutory language itself defines the standard of care, which makes it easier to establish the duty and its breach.
How Other States Have Responded
The Tarasoff decision was California law, with no binding force elsewhere, but its influence spread. Most states have adopted some version of the duty, with meaningful variation in how they define and enforce it.
- Mandatory duty. Roughly 30 states require mental health professionals to take protective action when a patient threatens serious violence against an identifiable victim. In these states, inaction can produce liability.
- Permissive duty. About 17 states and the District of Columbia allow therapists to disclose threats and take protective action, but do not require it. These laws protect a therapist who chooses to warn, without punishing one who does not.
- No recognized duty. A handful of states have either rejected the principle or have no statute or case law on it.
Around ten of the states that recognize the duty do so through case law rather than statute. The rest have legislated it, and those statutes tend to specify the steps a therapist must take, who counts as a mental health professional for purposes of the rule, and what immunity applies. At least one state with a permissive statute forbids warning the victim directly and allows disclosure only to law enforcement, which creates its own complications for clinicians trying to comply.
The Tension the Ruling Left Behind
Nearly five decades on, the concern Justice Clark raised in dissent has not gone away. A patient contemplating harm who knows the therapist may be required to disclose has an incentive to say nothing, leaving the therapist without the information that would allow intervention. Critics argue that this dynamic makes the public less safe, not more.
Defenders of the duty argue that it has saved lives by forcing action where confidentiality norms might otherwise excuse inaction. Some clinicians have found the rule workable, and even helpful, when they address it openly at the start of treatment: telling a patient that confidentiality has limits, and explaining what kinds of disclosures may require the therapist to act, sets expectations before a crisis arrives.
The core difficulty is prediction. Therapists are not reliable forecasters of violence, and the Tarasoff standard requires high-stakes judgments about future behavior. Err toward caution and warn, and the therapeutic relationship may suffer. Err toward confidentiality and stay silent, and someone may be seriously hurt. The duty to protect does not resolve that dilemma. It assigns legal responsibility for one side of the error.