From the NY Sun:

WALTER HALLORAN, 83, 'EXORCIST' PRIEST

The Rev. Walter H. Halloran, a priest who took part in an exorcism that spawned the book and move "The exorcist," died Tuesday in Milwaukee. He was age 83.

Halloran was the last living Jesuit who assisted in the exorcism in 1949 at a psychiatric unit in St. Louis. He was a 27-year-old Jesuit scholastic at Saint Louis University when a priest called him to the psychiatric wing at Alexian Brothers Hospital.

The Rev. William S. Bowdern was trying to help a 14-year-old boy who he believed was possessed by a demon, and he needed a strong man to help control the boy.

"The little boy would go into a seizure and get quite violent," Halloran told the St. Louis Post Dispatch in 1988. "So Father Bowdern asked me to hold him. Yes he did break my nose." Halloran said he saw streaks and arrows and words like "hell" on the boy's skin.

A three-paragraph news account of the incident inspired William Peter Blatty to write his 1971 best seller "The Exorcist," which led to the movie a few years latter. Blatty's story featured a 12-year-old girl.

Halloran earned two Bronze Stars for serving as a paratrooper chaplain during the Vietnam War, the oldest airborne chaplain at the time at 48.