In 1966, authorities in Bergen County launched a probe of nine suspicious deaths at Riverdell Hospital, a small osteopathic facility located in Oradell, New Jersey. In each case, patients were admitted to the hospital for surgery and died of unrelated causes, before or after routine surgical procedures. Despite the identification and trial of a suspect on murder charges, this intriguing case is still unsolved.

Carl Rohrbeck, age 73, was the first to die, admitted for hernia surgery on December 12, 1965, and lost to a diagnosed "coronary occlusion" the next day. Four-year-old Nancy Savino was signed in for an appendectomy on March 19, 1966, her death on March 21 attributed to some "undetermined physiological reaction." Margaret Henderson, 26, was admitted to Riverdell on April 22; she died the following day, after successful exploratory surgery. On May 15, 62-year-old Edith Post was booked in for surgery, lost two days later to undetermined causes. Ira Holster, 64, entered Riverdell for gall bladder surgery on July 12, dying without apparent cause on the twenty-ninth. Frank Biggs was complaining of an ulcer when he checked in on August 20; a week later the 59-year-old patient was dead. Eighty-year-old Mary Muentener died on September 1, seven days after she was admitted for gall bladder surgery. Emma Arzt, age 70, was another gall bladder patient, admitted on September 18, dead by September 23. Eileen Shaw, 36, also lasted five days at Riverdell, dying on October 23, after a successful Caesarian section.

Hospital administrators launched their investigation on November 1, 1966, after a Riverdell surgeon found eighteen vials of curare -- most nearly empty -- in the locker assigned to Dr. Mario Jascalevich. An Argentine immigrant, Jascalevich -- dubbed "Dr. X" by the press -- moved to the United States in 1955, setting up his practice in New Jersey. Confronted with the vials of poison , he explained that he had been involved in personal experiments with dogs. No motive could be ascertained for homicide, and ten years passed before the state charged Jascalevich with five counts of murder, in May 1976. Formally accused of slaying patients Savino, Henderson, Rohrbeck, Biggs and Arzt, the 39-year-old physician surrendered his medical license pending resolution of the case.

At trial, in 1978, two of the murder counts were dismissed for lack of evidence . After 34 weeks of testimony, Jascalevich was acquitted by jurors On October 24, returning to his native Argentina a short time later. He died there, of a cerebral hemorrhage, in September 1984. The case of the curare deaths at Riverdell remains officially unsolved today.