“Live PD” shines a light on the hot-button issue of policing in America by presenting a transparent look at law enforcement on duty. Incorporating dash cams along with fixed rig and handheld cameras, the series captures the work of a mix of urban and rural police forces on a typical Friday night. As host, veteran journalist Dan Abrams gives insight into what viewers are seeing in real time. The series’ best moments are presented in “Rewind.”