Exorcism
In Catholic practice the person performing the exorcism, known as an exorcist, is an ordained priest. The exorcist recites prayers according to the rubrics of the rite, and may make use of religious materials such as icons and sacramentals. The exorcist invokes God—specifically the Name of Jesus—as well as members of the Church Triumphant and the Archangel Michael to intervene with the exorcism. According to Catholic understanding, several weekly exorcisms over many years are sometimes required to expel a deeply entrenched demon.
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.