But the laws didn't start working until police effectively started enforcing them, said Zimring, a law professor at the University of California, Berkeley.
Minority communities, Zimring emphasizes, paid a disproportionate price in kids stopped and frisked, and detained, but they also earned a disproportionate gain in crime reduced.
Zimring also touches upon the role of aggressive, stop-and-frisk policing in the violence decline, though he notes its impact is small, its costs potentially large.