In the mid 1960s, the first reports surfaced of the activities of a sexual assailant who came to be known as the "enema bandit." Disguised by a ski mask, he would enter the rooms of coeds at various college campuses (usually in Oklahoma, but he also showed up in Kansas, Oklahoma, and California).
Holding his victims at gunpoint, he would force them to remove their clothes, then he would tie their wrists and proceed to give them each an enema, always working "slowly and deliberately." His victims agreed that "he knew what he was doing." Otherwise, he didn't harm the women, releasing them when he was finished. His victims also described him as being "extremely polite." Before he left, he would take whatever money he could find.
The enema bandit remained at large for a decade before police finally caught him in 1975, identifying him as Michael Kenyon. From wikipedia:
After his arrest he was judged to be legally sane; in December 1975, he pleaded guilty to six counts of armed robbery and was sentenced to six to twelve years in prison for each count, but was never charged for the enema assaults. He was paroled in 1981 after serving six years.
The enema bandit inspired several songs: "The Illinois Enema Bandit" by Frank Zappa (1976), and "Salute to the Enema Bandit" by Henry Threadgill (1986).
Ironwood Daily Globe - Feb 9, 1972
St. Louis Post-Dispatch - May 5, 1975