There is widely held public perception that what a person shares with a mental health practicioner in private session is protected information, no matter the circumstance.

NOT SO, say the courts:

Two California Supreme Court rulings, called Tarasoff I and II, shaped the ground rules for a clinician's duty to warn and protect a patient from themselves, and/or a potential victim or crime from taking place.

Opinion: Mental illness an explanation not an excuse

The Tarasoff case arose when Prosenjit Poddar, a student at the University of California, Berkeley, told his therapist of his intention to kill fellow student, Tatiana Tarasoff.

The therapist informed campus police, who briefly detained the student, but released him after he appeared rational and promised to stay away from Tarasoff. No further action was taken, and Tarasoff was not warned of the potential threat. Two months later, in October 1969, Poddar stabbed and killed Tarasoff.

The decision in Tarasoff I says therapists have a duty to warn a potential victim of a threat, even if it violates doctor-patient confidentiality. Tarasoff II, an extension of the first ruling, says the therapist also has an obligation to protect the person by alerting the appropriate law enforcement agency.

The practicioner who was working with Holmes, the individual charged in the Aurora, Colorado mass killings has claimed she made notification to school threat assessment team members of his potential to do harm.