William Leonard Pickard is one of two people convicted in the largest lysergic acid diethylamide (LSD) manufacturing case in history. In 2000, while moving their LSD laboratory across Kansas, Pickard and Clyde Apperson were pulled over while driving a Ryder rental truck and a follow car. The laboratory had been stored near a renovated Atlas-E missile silo near Wamego, Kansas. Gordon Todd Skinner, one of the men intimately involved in the case but not charged due to his cooperation, owned the property where the laboratory equipment was stored.

On July 27, 2020, Pickard was granted compassionate release from federal prison 20 years into his sentence.

Prior to his arrest, Pickard was deputy director of the Drug Policy Research Program at the University of California, Los Angeles.

In 2015 Pickard published The Rose of Paracelsus: On Secrets & Sacraments, a 656-page autobiography that blends fiction and nonfiction. The book centers around six chemists in an international drug organization.[18] One of the Six tells Pickard, the book's narrator, that the making of psychedelics is not just following a recipe or formula but requires "the requisite spirit ... the purest intent, a flawless diamond morality". He says it's the same spirit described in Thomas De Quincey and Jorge Luis Borges's short stories about Paracelsus, the 16th-century physician and alchemist of Basel who resurrected a rose from its ashes: "there could be no creation for lack of faith and the trust of gold".

Writing while incarcerated, Pickard wrote the entire book with pencil and paper. In an interview with Seth Ferranti, Pickard recounted: "The Rose was handwritten in two years, without notes and based on recollection, but seemed too trivial to honor the reader. I destroyed the work in minutes, then began again. It took another three years to compose, then a year to edit the 656 pages."