What made Swango particularly dangerous was the cover provided by his medical credentials — a licensed physician moving between hospitals and countries, poisoning patients in settings built on trust. Estimates of his victims reach as high as sixty, though he admitted to only four deaths, a gap that reflects both the difficulty of detecting physician-perpetrated harm and institutional failures that allowed him to continue practicing after early suspicions arose. He remains one of the most extensively investigated cases of medical serial killing in American history.

At the center of the largest LSD manufacturing case in recorded history, Pickard's operation was significant enough that its disruption is widely credited with causing a dramatic collapse in the drug's global supply. The 2000 arrest — made during the relocation of a clandestine laboratory hidden in a decommissioned missile silo — revealed the scale of an enterprise that had supplied a substantial portion of the world's LSD for years. He served two decades of a life sentence before compassionate release in 2020.