When a young man is gunned down outside a Cincinnati nightclub, witnesses see another young man running from the scene. Detectives Doug Lindle and Matt Thompson hope one of their witnesses can identify the shooter and help them catch a killer on the run. In Miami, a pair of one-year-old twins cry helplessly in the back of a black SUV — their mother slumped over in the driver’s seat, shot dead. Detectives Manny Castillo and Carlos Castellanos pursue every mysterious lead, hoping to find one that will identify their shooter.