Jack Nicholson was among A-listers up for the part of father Karras.
According to Friedkin, Paul Newman also wanted to portray Karras
Three A-list actresses of the time were considered for Chris. Friedkin first approached Audrey Hepburn, who said she was willing to take the role but only if the movie could be shot in Rome
Anne Bancroft was next. She, too, was willing but asked if production could be delayed nine months as she had just gotten pregnant. Friedkin declined her request as he could not wait that long; he also did not think the material was something she would want to be working on while tending to a newborn
Jane Fonda, next on the list, turned down the film as a “piece of capitalist rip-off bullshit”
The actual exorcism that inspired the movie happened at the Alexian brothers hospital in south St Louis, Missouri. They performed the exorcism in the psychiatric wing of the hospital.
It can believe that Roland was possessed due to his use of the ouija board that his Aunt introduced him to.
The entity possessing Roland caused furniture to move and random objects to levitate by themselves.