One of many terms used to describe the police. It is widely used outside of Los Angeles as well.
PART(S) OF SPEECH:
I go around the corner what do I see?
Po Po's followin me
Askin for my ID whos car I'm driving
Po Po's botherin me
Got me in a lineup, got my hands in cuffs
They don't wanna set me free
Trying to bring me down, when they come around
Po Po's fuckin with me
--Fabolous feat. Nate Dogg, "Po Po"