It has not stood the test of time very well.
The music is great. It really paints a picture and compliments whatever is on screen. Here's someone who is out to actually do good and not be a useless piece of shit like some cops. It's cool to see how he's unraveling how the police department actually works. Here's a cop who's understandable and has his head on right.
Fucking phenomenal acting, even from the smaller parts like the girl was getting raped. Good humor and a good amount of New York wit.
This movie rolls along so smoothly, that it's extremely easy to watch. That's supreme writing right there. I'm really digging Al Pacino's style in this movie, it's groovy. It must be hard trying to do good and be a humane person when your surrounded by schmucks and people who play dirty and do things for money, but Serpico, that's another story. He's got his head on right. It's pretty insane to see the situation he puts himself in.
It's amazing how the use of different camera angles can define a certain scene. A camera over the shoulder looking down, the camera obscurely showing something. Fucking fantastic movie! He chose Switzerland as the country to get away. No better country.
Focusing the whole feature i.e. of more than 2 hours only on a single character needs content and enough material to feed the audience which they easily provide with gripping screenplay to not let them wander off the screen even for a frame. Sidney Lemut still needs some better work on his execution and editing but that barely factors in here as the adaptation is way too smart and ahead of its time. Al Pacino is literally the heart of it; he beats fast and hard that helps it pumping and keeping the viewers alive for this glorious experience. Serpico breeds power, corruption, rage and politics on screen and successfully delivers it to the audience communicating through stellar performances like never before.
Parts of the movie feel campy, while the portrayal of corrupt cops could have been written with an emphasis towards subtly and nuance.
Perhaps this is just being nitpicky. But at a time when these two gentlemen were making other films such as The Godfather, Network, and the aforementioned Dog Day Afternoon, all of a sudden Serpico feels a bit more second-rate.