Very curious, the telling of this story. And very un Lumetlike. Not only is it somewhat non-linear, but it is done in a kind of telegrapheze. The scenes are almost jump cuts of each other. Serpico's mustache-beard becomes the time frame, and as a side bet, his frenetic wardrobe. Has a man ever worn more hats, almost like he is badly in search of a character.
For me, this movie was something of a one trick pony, very tiresome after the first few minutes. Okay, I get the point, you don't like cops on the take, and for the rest of the film mostly you watch them gobble the money, until finally in the last few minutes you go to a newspaper.
Not a single scene I would ever want to see again.
Whereas The Fugative Kind, The Verdict, plenty of those scenes I have watched over and over again.
Though at least this is early Pacino, and he is not trying to yell his fellow actors off the screen.