Nathan Fillion, who plays a mystery novelist shadowing an NYPD officer in the show "Castle", in this episode plays an actor in a crime show who acts like he is the cop
Boyle says "Desperate times call for Desperate Housewives". Nathan Fillion who appears in this episode played Adam Mayfair in Desperate Housewives.
The design of the show logo for "Serve & Protect" is clearly meant to echo that of "Law & Order".