Professor Richard Rosenfeld is a criminologist who has studied the supposed "Ferguson Effect," a term coined to explain the spiraling violence in big cities with large minority populations. Does it stem from de-policing? Can it be attributed to minority communities' plummeting trust in police, perhaps due to the Black Lives Matter movement? Does it exist at all? Dave Ross wades through the full range of issues and the latest data on the matter with Professor Rosenfeld.