SOURCES: The information provided on this site was gathered from many sources. Primary sources fall into five categories:

  1. Official documents, including police reports, FBI files, death certificates, autopsy reports, court records, crime scene photographs, and more
  2. Interviews conducted by this author
  3. Newspaper and magazine articles, as well as Internet publications.
  4. Television and radio broadcasts
  5. Other sources, such as books, letters, emails, photographs and other miscellaneous items.

Information concerning the crimes and the investigation was obtained from FBI files dating 1966 – 1994, reports from the Vallejo Police Department, the Benicia Police Department, the Napa County Sheriff’s Office, the Riverside Police Department, the Sonoma County Sheriff’s Office, the San Francisco Police Department, the California Department of Justice, the Los Angeles Police Department, the Patterson Police Department and more.

Information concerning Arthur Leigh Allen was obtained from reports by the San Francisco and Vallejo Police Departments, the Sonoma County Sheriff’s Office, FBI files, arrest reports, search warrants affidavits, parole reports, court records, public records, private letters, emails, interviews, newspaper and magazine articles, television broadcasts, the Internet and more.

Most of the information concerning handwriting analysis and the suspected “Zodiac” fingerprints was obtained from officials documents, including FBI files, and the various departments cited above, as well as interviews and photographs.