Marshall Applewhite

Marshall Herff "Do" Applewhite Jr. (May 17, 1931 – March 26, 1997) was an American cult leader. He co-founded what became known as the Heaven's Gate religious group and organized their mass suicide in 1997, which killed 39 people. Applewhite was born in Spur, Texas. 
In 1954, Applewhite was drafted by the United States Army and served in Austria and New Mexico as a member of the Army Signal Corps.
Applewhite believed in the ancient astronaut hypothesis, which said that extraterrestrials had visited humanity in the past and put humans on Earth and would return to collect some people.
Applewhite killed himself during the Heaven's Gate mass suicide by drinking barbiturate at his Rancho Santa Fe, California mansion, aged 65.