Theophilus Riesinger, O.F.M. Cap., also known as Francis Xavier Riesinger (February 27, 1868 - November 9, 1941) was a German American Capuchin friar and Catholic priest, who later became widely known as an exorcist in the United States.
Riesinger was born in Germany. He later moved to the United States where he entered the Capuchin Order. He was ordained on 29 June 1899. In the summer of 1928, due to his previous experience in dealing with possessions, he was requested by the Bishop of Des Moines to conduct the rite of exorcism on a forty-year-old woman who was suspected of being possessed. While preaching a parish mission in St. Joseph Parish in Earling, Iowa, he asked the permission of the pastor to conduct the ceremony in the parish. Receiving that, he chose a convent of Franciscan Sisters on the outskirts of the town for its privacy.
After 23 days of performing the exorcism Riesinger was exhausted. Finally, two days before Christmas of that year, the demons were finally driven out and the woman cried, "My Jesus! Mercy! Praised be Jesus Christ!"
The case became famous worldwide and was written about, in Germany, by the Rev. Carl Vogl. This article was seen and was translated into English in 1935 by a Benedictine monk of Saint John's Abbey in Minnesota, Celestine Kapsner, O.S.B., as Begone Satan. Riesinger himself wrote about the case in a 1934 book called The Earling possession case: An exposition of the exorcism of 'Mary', a demoniac. Another book about the case is The Devil Rocked Her Cradle, by David St. Clair (Dell, 1987).
Riesinger died on November 9, 1941. A necrology of Riesinger was placed on the Internet as part of the Capuchin Heritage Series.