Exorcism
In Catholic Christianity, exorcisms are performed in the name of Jesus Christ. A distinction is made between a formal exorcism, which can only be conducted by a priest during a baptism or with the permission of a bishop, and "prayers of deliverance" which can be said by anyone.
The Catholic rite for a formal exorcism, called a "Major Exorcism", is given in Section 11 of the Rituale Romanum. The Ritual lists guidelines for conducting an exorcism, and for determining when a formal exorcism is required. Priests are instructed to carefully determine that the nature of the affliction is not actually a psychological or physical illness before proceeding.
Tanacu exorcism
The Tanacu exorcism was a case in which Maricica Irina Cornici, a mentally ill nun at the Romanian Orthodox Church monastery of Tanacu in Vaslui County, Romania, was killed during an exorcism led by priest Daniel Petre Corogeanu and four Orthodox Christian nuns who were a part of the Order of the Holy Trinity. The case was widely publicized in the Romanian media and, following a lengthy trial, the priest was sentenced on appeal to 7 years, one nun to 6 years and the other three nuns to 5 years. They were all found guilty of deprivation of liberty resulting in the victim's death. They received a relatively lenient sentence, compared to the original desire of the prosecution who sought life imprisonment for the priest. Many of Tanacu's residents, including Cornici's brother, believed her to have suffered from demonic possession. The exorcism took place in June 2005.