There is no official training for an exorcist. Before a priest undertakes Exorcism, it has been found advisable-but not always possible or practical-for him to assist at exorcisms conducted by an older and already experienced priest.
Once possession has been verified to the satisfaction of the exorcist, he makes the rest of the decisions and takes care of all the necessary preparations. In some dioceses, it is he who chooses the assistant priest. The choice of the lay assistants and of the time and place of the exorcism is left to him.
The place of the exorcism is usually the home of the possessed person, for generally it is only relatives or closest friends who will give care and love in the dreadful circumstances associated with possession. The actual room chosen is most often one that has had some special significance for the possessed person, not infrequently his or her own bedroom or den. In this connection, one aspect of possession and of spirit makes itself apparent: the close connection between spirit and physical location. The puzzle of spirit and place makes itself felt in many ways and runs throughout virtually every exorcism. There is a theological explanation for it. But that there is some connection between spirit and place must be dealt with as a fact.
Once chosen, the ,room where the exorcism will be done is cleared as far as possible of anything that can be moved. During the exorcism, one form of violence may and most often does cause any object, light or heavy, to move about, rock back and forth, skitter or fly across the room, make much noise, strike the priest or the possessed or the assistants. It is not rare for people to emerge from an exorcism with serious physical wounds. Carpets, rugs, pictures, curtains, tables, chairs, boxes, trunks, bedclothes, bureaus, chandeliers, all are removed.
Doors very often will bang open and shut uncontrollably; but because exorcisms can go on for days, doors cannot be nailed or locked with unusual security. On the other hand, the doorway must be covered; otherwise, as experience shows, the physical force let loose within the exorcism room will affect the immediate vicinity outside the door.
Windows are closed securely; sometimes they may be boarded over in order to keep flying objects from crashing through them and to prevent more extreme accidents (possessed people sometimes attempt defenestration; physical forces sometimes propel the assistants or the exorcist toward the windows).
A bed or couch is usually left in the room (or placed there if necessary), and that is where the possessed person is placed. A small table is needed. On it are placed a crucifix, with one candle on either side of it, holy water, and a prayer book. Sometimes there will also be a relic of a saint or a picture that is considered to be especially holy or significant for the possessed. In recent years in the United States, and increasingly abroad as well, a tape recorder is used. It is placed on the floor or in a drawer or sometimes, if it is not too cumbersome, around the neck of an assistant.
The junior priest colleague of the exorcist is usually appointed by diocesan authorities. He is there for his own training as an exorcist. He will monitor the words and actions of the exorcist, warn him if he is making a mistake, help him if he weakens physically, and replace him if he dies, collapses, flees, is physically or emotionally battered beyond endurance-and all have happened during exorcisms.
The other assistants are laymen. Very often a medical doctor will be among them because of the danger to all present of strain, shock, or injury. The number of lay assistants will depend on the exorcist’s expectation of violence. Four is the usual number. Of course, in remote country areas or in very isolated Christian missions, and sometimes in big urban centers, there is no question of assistants. There simply is none available, or there is no time to acquire any. The exorcist must go it alone.