In Miami, Sgt. Louis Melancon and Det. Carlos Castellanos investigate the murder of two men savagely gunned down in the middle of a residential street. Detectives learn that a roommate of the two victim's is missing. Now they need to track him down to find out what he knows about the murders.

When a young man is gunned down outside a Cincinnati nightclub, witnesses see a 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.