[Gogar]

From "urban Dictionary"

1. POPO
A Police officer. especially the ones that rides on bikes.

Orgin: California late 80's

police officers that patrols certain beaches on bikes wore a vest that said PO in huge blockletters on each of their chest. which means Police Officer. they usually ride around in group of two's.

when you see them coming by. you see the word "PO" "PO" when they stand next to each other.

IMO it stems from certain parts of black slang because I remember when I was doing a lot of Gangsta Albums there were always rappers named "Dai Dai" and "Ree Ree" and "La La" and "Po Po" seems to fit right in.