In a Lonely Place (1950)

Hollywood screenwriter Dixon Steele (Humphrey Bogart) and his neighbor Laurel (Gloria Grahame) are just getting to know each other romantically when the police begin questioning Dixon about his involvement in the murder of a girl he met once. Certain her new love interest is innocent, Laurel stands by Dixon, but as the police continue pressing him, Dixon begins to act increasingly erratically. The blossoming love affair suffers as Laurel begins to wonder if Dixon really might be a killer.