The idea of a crazed poisoner taking out random kids on Halloween is terrifying, and seems somewhat plausible: After all, people have randomly killed strangers with poison. But there are no reports of anyone, ever, being poisoned by a stranger handing out Halloween candy. There are a couple of cases that are close, though.
Ronald Clark O’Bryan, aka “The Candy Man,” is the likely source for most Halloween hysteria. In 1974, Clark’s 8-year-old son Timothy died of cyanide poisoning soon after consuming a Pixy Stix on Halloween. Clark told police the Pixy Stix came from a house they’d visited while trick-or-treating. The investigation quickly ruled out the owner of the house and revealed that Clark had killed his own son to collect on the child’s life insurance. To cover up the crime, Clark gave poisoned candies to four other children. Miraculously, none of them consumed the powder.
The second case of a Halloween near-poisoning happened in 1964 on Long Island, N.Y. Helen Pfeil, a housewife, felt that some trick-or-treaters were too old for the holiday, so she handed out packages containing “ant buttons, steel wool pads, and dog biscuits” to older kids. She said it was a joke, but ant buttons contain arsenic, so no one else thought it was funny. The ant buttons were clearly marked “poison,” so they weren’t disguised as candy, and Pfeil said she told recipients of her special packages that they were meant as a joke, so it looks more like horrifically bad judgement than malice.