Force of Darkness (1985)

In a parking lot, Gloria Ramsey is the powerless witness to the murder of her life partner, a physician. On the scene of the crime, the police listen to the young woman's version but unfortunately the only prints found are hers. Detective Ben Johnson, who is convinced of her innocence, goes after the last patient who came to visit the doctor. To his surprise, the man happens to believe he is possessed by the devil...