Ep 2. Who is the Zodiac Killer?

In season 4 episode 2 of History's Greatest Mysteries, titled "Who is the Zodiac Killer?", the focus is on one of the most notorious unsolved crime cases in American history. The Zodiac Killer was a serial killer who operated in the late 1960s and early 1970s, and is known for sending cryptic letters and codes to local newspapers and law enforcement agencies. The killer is suspected to have murdered at least 5 people, and possibly many more, making it one of the most perplexing mysteries of our time.

The show delves deep into the case, exploring the history of the Zodiac Killer and the various theories that have been put forward over the years. The episode looks at the original investigations, the detectives who worked on the case, and the various leads that were pursued - many of which proved to be dead ends.

One of the key aspects of the episode is the use of new technology to try and unravel the mystery. Advances in DNA analysis and forensic science have given investigators new hope in solving the case, and the show details the efforts to use these tools to finally identify the killer.

The episode also examines some of the key suspects that have emerged over the years. From Arthur Leigh Allen, a man who was investigated by police and considered a prime suspect, to individuals who have surfaced in recent years claiming to know the identity of the killer, the episode explores the various theories and evidence behind each suspect.

Overall, the episode is a fascinating deep dive into one of the most enduring mysteries of our time. It offers new insights and revelations that shed light on the investigation, and brings the viewer closer than ever to understanding the truth behind the Zodiac Killer.