Exorcism
In Christianity, exorcism is the practice of casting out demons. In Christian practice the person performing the exorcism, known as an exorcist, is often a member of the Christian Church, or an individual thought to be graced with special powers or skills. The exorcist may use prayers and religious material, such as set formulas, gestures, symbols, icons, amulets, etc. The exorcist often invokes God, Jesus and/or several different angels and archangels to intervene with the exorcism. Protestant Christian exorcists most commonly believe the authority given to them by the Father, Son, and Holy Spirit (the Trinity) is the source of their ability to cast out demons.
Exorcism of Roland Doe
In the late 1940s, in the United States, priests of the Roman Catholic Church performed a series of exorcisms on an anonymous boy, documented under the pseudonym "Roland Doe" or "Robbie Mannheim". The 14-year-old boy (born circa 1935), was the alleged victim of demonic possession, and the events were recorded by the attending priest, Raymond Bishop. Subsequent supernatural claims surrounding the events were used as elements in the 1971 novel "The Exorcist" by William Peter Blatty and the 1973 film adaptation.