Bizarre self-taught "professional engineer" of
execution methods. He became a professional execution consultant and did consulting work on various US states' death chambers.
He later wrote a controversial
holocaust denying report in 1988 for
Ernst Zundel that stated
Zyklon B was not used to kill humans. His findings were discredited because Leuchter made many factual errors (indeed, he had no formal training in
engineering,
chemistry or
toxicology but instead obtained a BA in history in 1964).
Nizkor.org thoroughly discredited the
Leuchter Report online.
Leuchter was the subject of the 1999
Errol Morris documentary: "Mr. Death: The Rise and Fall of Fred A. Leuchter, Jr.".