L.A. Rex follows Ben Halloran from his first day as a rookie cop with the LAPD. Ben has been assigned to 77th Division; one of the toughest areas in L.A.'s South Central Area. Ben has been assigned to ride with Miguel Marquez, one of the last of old school of officers. Marquez is a legend in the 77th and if a rookie cop listens to him, he has a fighting chance of survival. But Ben isn't what he seems. He has his own agenda.