Was Arthur Leigh Allen the Zodiac Killer? Theories and suspects

According to Netflix, the primary focus of the documentary series is the Seawater family, who say "Allen played an integral role in their youth, caring for them and taking them on trips", some of whom feature in the documentary.

With the documentary now available to watch on Netflix, just who was Arthur Leigh Allen and was he really the Zodiac Killer?

Who was Arthur Leigh Allen?

While not much is known about Arthur Leigh Allen's early life, he joined the US Navy in 1951 before being honourably discharged in 1959.

Allen studied at California Polytechnic University and graduated in 1960 and from there, went on to become an elementary school teacher.

In 1962, Allen was fired from Travis Elementary School for having a firearm on school grounds.

He then became a teacher in 1966 at Valley Springs Elementary School before he was fired and subsequently arrested for child molestation.

According to Time magazine, he spent three years in prison and served five years of felony probation until 1982.

Who was the Zodiac Killer?

The Zodiac Killer is one of the most infamous unsolved serial killer cases, with no one ever convicted.

The Zodiac Killer murdered at least five people from 1968 to 1969 and wrote several messages in code and riddles, demanding they were published on the front page of newspapers in San Francisco.

Was Arthur Leigh Allen the Zodiac Killer?

Arthur Leigh Allen has been the only publicly identified suspect by the police, however there was never enough evidence to charge him.

Therefore, it cannot be confirmed whether or not Arthur Leigh Allen was the Zodiac Killer.

In the documentary, the Seawater siblings claimed that Allen confessed to being the Zodiac killer.

According to David and Connie Seawater, Allen would take them on weekend trips away or visits to the cinema, and it was during a sailing trip with Allen in 1991 that Connie claims she asked him if he was the Zodiac killer, to which he said that if he told her, he would have to kill her.

"I thought it was a big joke," Connie says in the documentary.

David Seawater claimed he got a full confession from Allen, who told him he was the Zodiac killer when his health was declining.

When David and Connie's mother Phyllis died in 2017, they found a box with letters between Phyllis and Allen, where he spoke about the Zodiac.

"Every time someone mentioned police to me, I'd jump," Allen wrote in a letter show in the Netflix series.

"Seeing a murder headline would turn my palms sweaty," another read, while a more revealing one read: "The most dangerous thing is when I almost decided to confess."

Other theories that sleuths have about Allen is that during the three years Allen was in prison, the murders and letters from the Zodiac killer stopped.

Allen was also identified by survivor Michael Mageau in a police line-up.

However, police were unable to charge Allen due to a conflicting witness testimony.

Where is Arthur Leigh Allen now?

Arthur Leigh Allen died in 1992.

According to an autopsy report, he died from arteriosclerotic heart disease.

This is the Zodiac Speaking is available to stream on Netflix now. Sign up for Netflix from £4.99 a month. Netflix is also available on Sky Glass and Virgin Media Stream.

Check out more of our Entertainment coverage or visit our TV Guide and Streaming Guide to find out what else is on. For more from the biggest stars in TV, listen to The Radio Times Podcast.