Continuity mistake: In the scene where Serpico is in his apartment speaking to his girlfriend explaining how hard it's been to be an honest cop, he is drinking what appears to be a full glass of white wine. In the following shot of the both of them, Serpico sets up two unused glasses, opens a bottle of wine and pours it into the two glasses. His original full glass of wine is nowhere to be seen.
Continuity mistake: Talking with his new and still wet behind the ears boss, Rizzo advises him against trying to blitz the one-handed delinquent. He is making a gesture with his right hand, but at the cut here he is moving his left hand instead, with the arm that suddenly is on the table. (00:27:15)Sammo