Investigation of a Citizen Above Suspicion (Italian: Indagine su un cittadino al di sopra di ogni sospetto) is a 1970 Italian crime drama film directed by Elio Petri, starring Gian Maria Volonté and Florinda Bolkan. It is a psychological, black-humored satire on corruption in high office, telling the story of a top police officer who kills his mistress, and then tests whether the police would charge him for this crime. He begins manipulating the investigation by planting obvious clues while the other police officers ignore them, either intentionally or not.