Was the Exorcist movie based on a true story?

Related questions

1. Is the Exorcist 1973 a true story?
2. Did inhumans get Cancelled?
3. Do you have to be a priest to do an exorcism?
4. Is Michael Myers true story?
5. Is the Exorcist series on Netflix?
6. Who starred in the original Exorcist?
7. What does it take to be an exorcist?
8. Why was Texas Chainsaw Massacre banned?
9. Can an ordained minister perform an exorcism?
10. Who died in the making of The Exorcist?

Tags

1. #jesuit
2. #maryland
3. #blatty
4. #exorcism
5. #based
6. #story
7. #priests
8. #realize
9. #assigned
10. #peter
11. #roland
12. #movie
13. #pseudonym
14. #months
15. #novel