Do you truly honestly believe the desire to seek retribution is not a common motive for violent crime? A significant amount of gang-related violence is based on that very desire.

"You're an adult and you can survive a 3-hour flight without taking a fucking nap."

They wear uniforms in the same color as that of the NYPD but they have no peace officer powers and can't write citations for moving violations. So in essence, still not cops.