The Zodiac investigation includes efforts to identify the killer using DNA recovered from evidence, including the letters, envelopes, and stamps sent by the Zodiac. Early efforts to obtain DNA evidence began in the 1990s and continued years later as new advances in technology and forensic science identified other infamous and elusive killers such as Gary Ridgway aka The Green River killer, Dennis Rader aka the BTK strangler, Joseph DeAngelo aka The Golden State killer, and many others. According to some reports, DNA evidence obtained from suspected Zodiac communications did not match various suspects. The search for DNA which could identify the Zodiac killer remains the subject of speculation and controversy.

ZODIAC DNA: The Silver Bullet * ZODIAC DNA: The Magic Bullet * ZODIAC DNA: Questions