True Confessions (1981)

Synopsis
Adapted by John Gregory Dunne and Joan Didion from Dunne's novel, True Confessions uses the still-unsolved "Black Dahlia" murder as the foundation for a devastating attack on big-city corruption -- in which it appears that many of the perpetrators wear clerical collars. In, 1948 Los Angeles detective Tom Spellacy (Robert 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 (Robert De Niro), is reluctantly currying favor with crooked contractor Jack Amsterdam (Charles Durning), 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. ~ Hal Erickson, All Movie Guide