you have a symbiotic relationship between organized crime, often violent. the local police and political establishment. >> reporter: in one of mexico's most prosperous cities, people are too scared to talk about the fire. but not simona perez. >> i'm not afraid. i lost my fear when i lost my son in that casino. i want mexico to change. >> reporter: she hold onto the ashes of her son who would have turned 19 today. the policeman who was arrested has begun to talk about what happened. the cartels have killed his mother, and brother. alisyn: it's the newest sanctuary city. we'll tell you where his are no longer allowed to enforce immigration law.