While I know Santa Monica used to have a huge gang population about 10 years ago in the neighborhoods between Santa Monica College and Santa Monica High School and generally south of the 10 freeway, that area has since gentrified quite heavily and LAPD maps shows insignificant gang activity in those neighborhoods.

I would be very surprised to see that there ever was any significant street gang activity in Beverly Hills, since that municipality spends a significant amount of money on street patrols to keep criminal activity low. Moreover, Beverly Hills is a fairly racially homogenous city...