What issues did Frank Serpico stir in the New York City Police Department that had not been broached in its long history?

What issues did Frank Serpico stir in the New York City Police Department that had not been broached in its long history? Did his valiant efforts to reform the department meet with acceptance from the police brass? Were the changes in departmental regulations instituted by the Knapp Commission – inspired by Serpico’s allegations – ever really adhered to by the rank and file cops? Would you say that Frank Serpico is considered today a model peace officer or a self-aggrandizing trouble maker that thrived on the attention he created?