As a result of this rebuff Poddar underwent a severe emotional crisis. He became depressed and neglected his appearance, his studies and his health. He remained by himself, speaking disjointedly and often weeping. This condition persisted, with steady deterioration, throughout the spring and into the summer of 1969. Defendant did have occasional meetings with Tatiana during this period and tape recorded various of their conversations in an attempt to ascertain why she did not love him.
During the summer of 1969 Tatiana went to South America. After her departure Poddar began to improve and at the suggestion of a friend sought psychological assistance. Prosenjit Poddar was a patient of Dr. Lawrence Moore, a psychologist at UC Berkeley's Cowell Memorial Hospital in 1969. Poddar confided his intent to kill Tatiana. Dr. Moore requested that the campus police detain Poddar, writing that, in his opinion, Poddar was suffering from paranoid schizophrenia, acute and severe. The psychologist recommended that defendant be civilly committed as a dangerous person. Poddar was detained, but shortly thereafter released, as he appeared rational. Dr. Moore's supervisor, Dr. Harvey Powelson, then ordered that Poddar not be subject to further detention. In October, after Tatiana had returned, Poddar stopped seeing his psychologist. Neither Tatiana nor her parents received any warning of the threat. Poddar then befriended Tatiana's brother, even moving in with him. Several months later, on October 27, 1969, Poddar carried out the plan he had confided to his psychologist, killing Tarasoff. Tarasoff's parents then sued Moore and various other employees of the University.
Poddar was convicted of second-degree murder, but the conviction was later appealed and overturned on the grounds that the jury was inadequately informed. A second trial was not held, and Poddar was released on the condition that he return to India.
In the majority opinion, Justice Mathew O. Tobriner famously stated: "... the confidential character of patient-psychotherapist communications must yield to the extent that disclosure is essential to avert danger to others. The protective privilege ends where the public peril begins."
Justice Clark dissented, stating in his minority opinion that "the very practice of psychiatry depends upon the reputation in the community that the psychiatrist will not tell".