True Confessions (1981)

In, 1948 Los Angeles detective Tom Spellacy (Duvall) is assigned to investigate the death of a priest, who apparently suffered a heart attack while being serviced by a prostitute. Meanwhile, Tom's brother, young Catholic monsignor Des Spellacy (De Niro), is reluctantly currying favor with crooked contractor Jack Amsterdam, the better to finance an expansion of Des' church. The unifying factor between Tom and Des, beyond their sibling relationship, turns out to be the grisly murder of a hooker. The key words in the labyrinthine proceedings are power, ambition, and hypocrisy.