Shortly before noon on August 28, 1976, after partying all night in the beach town of Oceanside, California, with her new boyfriend Allan "Butch" Koven and others, Jones was found dead in a bedroom of a house belonging to the father of a 14-year-old friend named Helen Hennessy.[4]:28 The coroner's report listed her death as a drug overdose, later ruled accidental;[6] cocaine, PCP, Quaalude, and Seconal were found in her body during an autopsy toxicology examination. The police report also indicated a small vial of blue liquid next to Jones at the scene, which was never identified. The coroner who examined Jones reported she died from one of the most severe drug overdoses he had ever seen. Jones was 18 years old.[4]:28
Jones had no funeral. She was cremated, and her ashes were scattered over the Pacific Ocean.[6] She left $63,000 in cash and more than $100,000 in savings bonds when she died.
Six days after Jones' death, Dr. Don Carlos Moshos was arrested and charged with illegally prescribing Seconal to Jones,[7]among other drugs-for-profit charges from a concurrent undercover criminal investigation. An envelope with Moshos' business address was present at Jones' scene of death, specifying a drug found in Anissa's toxicology report (Seconal), its dosage (1.5 gr), quantity (50), and the recipient's last name (Jones). Moshos was charged with 11 offenses, including second-degree murder;[8] while awaiting trial, Moshos died of cancer by acute viral hepatitis on December 27, 1976, four months after Jones.[9] Although the murder charges were dropped before his death, Moshos' estate was sued by Jones' surviving family for $400,000; in July 1979, the verdict found him 30% liable and Jones 70% responsible for her death, and the resulting judgment was reduced to $79,500.
On March 15, 1984, Jones' brother Paul also died of a drug overdose. He was 24 years old.[4]:29 On January 14, 2012, their mother, Mary Paula Tweel, died in Detroit, Michigan. Jones' father, John Paul Jones, Sr., had died of heart failure on March 7, 1974, and there were no surviving heirs to the family name.