Today solemn exorcism is limited to the priest who prays in the name of the church. There are three requirements in order for this rite to be performed; the person must be possessed, a priest must perform the exorcism, and finally an exorcism could only be performed with the permission of the bishop.

With private exorcism a lay-person or religious can pray in his/her own name (not in the name of the church). What this means is the laity cannot use the Roman Ritual of Exorcism to pray in the name of the church.

Before Vatican II the exorcism prayer was part of the Baptismal rite. Why? In the days of the early church there were many pagans coming into the church. Part of the long preparation for these pagans coming into the church was exorcism on Holy Saturday before Easter.

Around the third century, Pope Cornelius was the first to make the exorcist a minor order He announced that an exorcist could be a priest, deacon or in the subdiaconate. The minor order of exorcism has since been dropped by Pope Paul VI in 1972. He did not believe there was a need and it was obsolete.

An exorcist is to be a priest (sacerdos) not a presbyter (presbyterus) as in the canon, which means bishops as well as presbyters may be appointed exorcists.

The priest must have specific preparation for this office.

"For the most part" (plerumque), the local ordinary who appoints the exorcist should be the diocesan bishop, which implies that the vicar general and episcopal vicar should not do it without a special mandate, except in a case of need when the bishop cannot be reached.

The exorcist, whether appointed to the stable office of exorcist or ad actum, is to fulfil this ministry under the direction of the diocesan bishop.

Considered an "ancient" ritual and is snubbed by most religious leaving many victims to suffer indescribable torments, and in some instances, even suicide.

The story of Anneliese Michel

Anneliese Michel was brought up in a hard-working, faithful catholic family. She was a typical girl who moved to a big city after receiving a scholarship. Not long after starting classes, this 19-year-old college freshman began exhibiting bizarre behavior, typical to those who were thought to be possessed.  Distraught, Anneliese then seeks medical advice and the doctor tells her that she experienced a grand-mal seizure and that she has epilepsy. Anneliese then turns to her priest who believes that she is possessed by an evil force. As time passes, it is clear to the priest and her parents that an exorcism must be performed to save her. It was approved by the diocese and began, strangely enough, on Halloween. Lasting for several months, the procedure took it’s toll on Anneliese, the priests, and her family. Anneliese was often violent and her behaviour was what "normal" people would find repulsive. She engaged in self-mutilation, attacked family members, ate insects, was verbally abusive, and destroyed religious symbols. This all takes it's toll and Anneliese dies a tragic death in 1976, embarrassing the church and outraging others.

Forensic evidence concludes that Anneliese starved to death and subsequent investigations into her untimely death leads to arguments as to whether Anneliese was really possessed by evil spirits or had epilepsy. Two priests and her parents (who truly believed that she was possessed) were accused of negligent homicide and later found guilty of manslaughter.

Robbie Doe

Another  famous exorcism movie starring Linda Blair was based on a real incident, one that took place in 1949. Robbie Doe has never been identified but he was supposedly possessed after using a Ouija board.  He was taken to the Georgetown Hospital where he started to receive an exorcism from Father Edward Hughes. Father Hughes was five minutes into the ritual when the boy somehow dislodged a spring from the bed and stabbed him with it. The gash required 100 stitches.
The family moved to St. Louis where the boy underwent another exorcism, this one lasting six weeks. Just like the movie, the bed would shake and objects flew across the room of their own accord. Marks would appear on Robbie’s body, including the word "Evil". Finally, the exorcism succeeded and the boy was able to live a normal life, not remembering much about what happened.
Such a view seems contrary to the findings of the physician and psychiatrist who deemed the boy physically and mentally healthy while he was experiencing these troubles.

40 year old woman

Father Theophilus Riesinger brought a 40-year-old woman from a neighbouring community to the Franciscan convent in Earling to undergo an exorcism. Despite being very religious, the woman said she was unable to enter a church or pray since she was 14. She also spoke in languages she didn’t know, was abnormally strong and couldn’t stand to be around Holy Water or anything that had been blessed.
The evening the woman arrived, a nun who prepared dinner sprinkled the meal with Holy Water to bless the food. When the woman was given her plate, she freaked out and demanded an unblessed plate.

She spoke in different languages and different voices and named sins that people in the room had committed. On the 23rd day of the ordeal, Father Theophilus sensed that the demons were weakening and blessed her. The woman started howling and screaming the names of the demons inside of her; when the last name was uttered the woman opened her eyes and was reportedly able to speak the name of Jesus again for the first time in years.

Teenager at the Vatican

Pope John Paul II reportedly performed an exorcism on a 19-year-old girl at the Vatican in 2000. Father Gabriele Amorth, the official exorcist for the Diocese of Rome, had attempted to exorcise the girl the day before and failed. Her parents brought her to Pope John Paul II's Wednesday audience in St. Peter’s Square in hopes that a Papal blessing would do her some good, but apparently it just incensed her even more. Italian newspapers wrote that the girl started screaming insults at the Pope in a "cavernous voice" and struggled with guards with superhuman strength. The Pope was informed about her and spent 30 minutes with her. When the Pope left, the girl said (in a voice apparently not belonging to her), "Not even the head of the church can send me away."