The still of Sgt Grey (Richard T Jones) as a rookie is from the actor's role in "Phonebooth" , not "NYPD Blue" as some seem to mistakenly believe.
Smitty's first name is revealed as Quigley.
The Hip-Hop group Flex 'N Flow seems to be modeled on the group Kid 'N Play, down to the "kick step" maneuver. As for any controversy surrounding the inspiration for the contemporary group is unknown.