In the wake of Freddie Gray's death, the Justice Department has launched a civil rights investigation into the conduct of the Baltimore's police force. 

Here in the West, police departments are facing their own challenges and inquiries. Earlier this year, disturbing text messages sent between officers in San Francisco came to light. Some were homophobic, others were racist. Some messages spoke of lynching African-Americans and burning crosses.

San Francisco District Attorney George Gascón announced a broader inquiry into whether the police and sheriff's departments have a deep-seated culture of systemic bias leading to unlawful arrests. He joins the show with more.