Rumors of Devil-worship, or Satanism, have circulated for centuries. Tales of Black Masses, demonic possession, mysterious nighttime ceremonies, and human sacrifices have captured the popular consciousness, prompting the Christian Church to move aggressively to root out Satanism and its practioners through often extraordinarily brutal means of detection and interrogation.

Until recently the stuff of myths and stories, allegations of occult worship have of late taken the form of police investigations concerning ritual child abuse, teens involved in Satanic cults, and serial killings....