The hard-boiled private eye coolly strolls a few steps ahead of the audience. The slapstick detective gets everything wrong and then pratfalls first over the finish line anyway.
Jake Gittes (Jack Nicholson) is neither – instead he's a hard-boiled private eye who gets everything wrong. Jake snaps tabloid-ready photos of an adulterous love nest that's no such thing. He spies a distressed young woman through a window and mistakes her for a hostage. He finds bifocals in a pond and calls them Exhibit A of marital murder, only the glasses don't belong to the victim and the wife hasn't killed anyone. Yet when he confronts ostensible black widow Evelyn Mulwray (Dunaway) with the spectacular evidence, the cigarette between his teeth lends his voice an authoritative Bogie hiss.
Throughout, Nicholson sexes up mediocre snooping with blithe arrogance and sarcastic machismo. It's the actor's default mode, sure, but in 1974 it hadn't yet calcified into Schtickolson, and in 1974 a director (Polanski), a screenwriter (Towne) and a producer (Evans) could decide to beat a genre senseless and dump it in the wilds of Greek tragedy.
'You see, Mr Gits,' depravity incarnate Noah Cross (Huston) famously explains, 'most people never have to face the fact that, at the right time and the right place, they're capable of anything.' As is Chinatown. The last gunshot here is the sound of the gate slamming on the Paramount lot of Evans' halcyon reign, and as the camera rears back to catch Jake's expression, the dolly lists and shivers - an almost imperceptible sob of grief and recognition, but not a tear is shed.