Delitti a soggetto

An apparently peaceful individual wanders around infamous places in the middle of the night and, attacked by thugs of all kinds, reacts by eliminating them with gunshots. Before leaving the crime scene, he numbers his victims with bingo balls. This curious mania reminds Bliss, a journalist who intervened at the scene of one of the crimes, of an old film of the "Vigilante", a character from a series of b-movies from the seventies. It's a faint trace, but it leads Nick to question the protagonist of those films...