I must know. I haven’t read the whole thread, so perhaps it is answered within. But the slang po-po for police: never heard it before. Is it a Southernism (Atlanta)? Is it meant to be cute, like flatfoot, or insulting, like pig? How old a term is it? Did Askia make it up? In which case, we must try to get it into the vernacular, so the SDMB can have invented a word!
[Margaret Dumont] “I say, I wonder where the opera house is? I’ll ask that po-po!” [/Margaret Dumont]
Very very common here on the west coast. Certainly a slang/underground term.
In German a “popo” is your ass, and while I understand that some policemen can be asses, I don’t think this is the origin of the slang term as we use it.
Hope not, anyway. 
Q
I wondered pretty much the same thing Eve. I had no idea what a popo was and why they would shoot the guy’s neighbor.
I figured out what it meant, but I thought it was an awfully weird way of saying it.
Those young people and their wacky slang!
Lived on the West coast all my life, never heard it. Even saw that beach patrol.
I hear it all the time here in california.
I live in the midwest and have heard it mainly from those in the meth/drug/underground culture.
That’s what we called it when we were kids.
I did too in my college days in the 80’s.
Heard it for 15+ years. It’s specifically black/ghetto slang.
I believe that I first saw it used in Homicide: A Year on the Killing Streets. At any rate, I have heard it used by people in Baltimore, usually West Baltimore African-Americans.
I first heard it from a white kid up here in small-town Vermont.
Count me among those who grew up hearing po-po as a name for your backside.
My mom even had this silly little diaper changing song that she used to sing that contained the phrase “pat 'em on the po-po”.
Another Californian here that has heard the term for a long time now.
FWIW I’ve always heard it to refer to “the police”, plural. So the “I’ll ask that po-po!” example would be unusual.
Exactly … much like saying “the fuzz”. A collective noun.
I’ve heard for a good 15 years, at least, from folks of all stripes.
I’ve heard it plenty in Minneapolis, both in the plural and the singular.
Another Californian weighing in with “Heard it for quite awhile, always collectively.”