After a brief historic review of satanism, the document describes various types of involvement in satanic beliefs and rituals and their association with various criminal behaviors. The religious satanists, the most notable of which are the Church of Satan, Church of Satanic Liberation, and the Temple of Set, provide a context for groups to participate in traditional satanic rituals. Although there have been recent investigations into alleged activities of individual members of these groups, there has been little criminal activity linked to the organized churches. “Experimentalists” are defined as youths who dabble in satanism and drugs coupled with suggestive heavy metal music, horror videos, and fantasy role-play games. Criminal activities traced to such experimentalists have included trespass, burglary, criminal damage, drug use, homicide, and suicide. Suicide is a significant problem often associated with written pacts with the devil. A “self-styled satanist” is a sociopath, psychopath, or drug addict who justifies criminal acts through a belief system centered in Satan. Groups in this category include outlaw motorcycle gangs, extremist groups, drug-dealing organizations, prison inmates, and serial killers. A “satanic cult” is a relatively cohesive group of persons, akin to “self-styled satanists,” who subscribe to the perpetration of evil in a variety of ways. These cults are often composed of persons with severe mental and behavioral problems who are attracted to satanism because it condones and encourages antisocial and deviant behavior. “Orthodox satanic groups” are intergenerational as they pass their belief systems, rituals, and coven structure from one generation to the next. Criminal acts attributed to these groups range from kidnapping and drug dealing to ritual child abuse, human sacrifice, and cannibalism. Questions and answers on the material are included.