Allard Kenneth Lowenstein was 51 when he was fatally shot in his Manhattan law office in Rockefeller Center on March 14, 1980. Dennis Sweeney, described as a former student and one-time protégé of Lowenstein, entered the office, spoke briefly with him, then produced a 9mm semiautomatic pistol and fired multiple times. A nearby telephone installer heard screams and several pops. Sweeney left the weapon on a secretary’s desk, lit a cigarette, and awaited police; he surrendered without resisting.

Lowenstein was taken to St. Clare’s Hospital, where surgeons operated for more than five hours, removing his left lung and repairing multiple heart wounds, but he was pronounced dead shortly after 11 p.m. The investigation identified Sweeney as suffering from paranoid schizophrenia and holding delusions that Lowenstein was persecuting him and had caused his father’s fatal heart attack. Sweeney was arrested, charged with second-degree murder and weapons possession, found not guilty by reason of insanity in February 1981, and committed to Mid-Hudson Psychiatric Center.