In 1952, he was working as a theater booker in Clarksburg, West Virginia when he began collecting stories about the Flatwoods Monster, an alleged extraterrestrial reported by residents of nearby Braxton County.

[3] In 1953, Albert K. Bender abruptly dissolved his organization, claiming that he could not continue writing about UFOs because of "orders from a higher source".

Before dying in 1984, Barker wrote a final book about the Men in Black, called MIB: The Secret Terror Among Us.

The letter was written on State Department stationery, and Barker himself described it as "one of the great unsolved mysteries of the UFO field" in his 1967 Book of Adamski.

In the story, Sherwood (writing as "Dr. Richard H. Pratt") claimed he was ordered to silence by the "blackmen" after learning that UFOs were time-travelling vehicles.

"[5] The concept of the Men in Black, which Barker introduced in They Knew Too Much About Flying Saucers, has become a major part of UFO lore.

Barker himself became the subject of two documentary films: Whispers From Space (1995), which was created by The Last Prom,[6] and Shades of Gray (2008), which was directed by Bob Wilkinson.