Contention on this entry is also expected, if only minimally warranted. Sure, he's not technically a private eye in the strictest of senses, but rather a surveillance expert (isn't that really what a P.I. is, though?) highly regarded in his field. The brilliance of the character, in a script written by Francis Ford Coppola, is that he's conversely obsessed with his own privacy. Always the professional, Caul becomes racked with guilt when a conversation he records leads to the death of three individuals. After editing a series of recordings of the same conversation taken from different vantage points, Caul begins to notice tones and undercurrents that start to trouble him. Throughout the film, he continues to refine the recordings, uncovering new nuances in the conversation. When he uncovers the phrase "He'd kill us if he got the chance," Caul is placed in a moral dilemma and forced to ask himself if he can continue to keep himself removed from his work.