Cop 1 & 2 are both kraang operatives posing as police officers.
They then made their final appearance in The Invasion when they attempted to arrest Casey for loitering [with him asking them how they know his name as he tries to get loose in the process]. When the The Kraang start the invasion, Casey accidentally hits the officers with his hockey stick. this causes the officer to turn around and reveal that he's really a Kraang spy. The officer cop then follows suit and reveals that he's spy as well. Ralph then helps Casey dispatch them both.
One of the officers is Caucasian while the other is African-american. Once it is revealed that their Kraang spies, they both appear as regular kraang in Robotic Bodies.
After the events in The Invasion, it is unknown if there are any real cops in New York; however, after the events in Battle for New York, it is a possibility. It is now must likely [as seen in Casey Jones VS. The Underworld when Casey narrates in the opening of the episode when he states that everyone's getting back to their regular lives and cleaning up the city after the kraang invasion.