William Peter Blatty — American Writer born on January 07, 1928,

William Peter Blatty is an American writer and filmmaker.The Exorcist, written in 1971, is his most well-known novel; he also wrote the screenplay for the film adaptation, for which he won an Academy Award, and wrote and directed the sequel, The Exorcist III... (wikipedia)

And the sad truth is that nobody wants me to write comedy. The Exorcist not only ended that career, it expunged all memory of its existence.
Horror does not interest me, and so I know little of its practicioners, old or current.
Well, the research into it affected me. And the novel, it very much strengthened my faith.
I've been campaigning like anything for restoring these changes. For 27 years. I wrote a book about it, well, a portion of the book was devoted to these scenes and why they should have been in the movie.
I have never read horror, nor do I consider The Exorcist to be such, but rather as a suspenseful supernatural detective story, or paranormal police procedural.