Malachi Martin
From Conservapedia
Malachi Martin (1921 - 1999) was a Catholic priest and Jesuit who became a very prolific author of both fiction and non-fiction books. He asked, and was granted, to be allowed to be freed from his vows to the priesthood and the Jesuits. Some of his books were critical of aspects of Catholicism and the Jesuits, but he always supported the Pope.
One of his many books was Hostage to the Devil, where he recounted his active participation in performing exorcisms.