St. Louis University, Michelle Peltier / AP
In this photo provided by St. Louis University, the Rev. John Padberg, S.J., director of the Institute of Jesuit Sources, speaks during a panel discussion at St. Louis University in St. Louis, Tuesday, Oct. 29, 2013, about the month-long 1949 demon-purging ritual at the school’s former Alexian Brothers Hospital. The treatment of an unidentified suburban Washington, D.C., boy formed the basis for the 1971 novel by William Peter Blatty, The Exorcist, and the film of the same name two years later. Listening from left to right, are: Thomas B. Allen, author of Possessed: The True Story of an Exorcism, and John Waide, archivist at Saint Louis University.