Jack Lowery (Titus Welliver) was a tough street cop coping with personal demons which included his selfish and nagging wife, Yvonne, who died early in the season. Lowery later started an affair with his female partner, Nona Valentine (Klea Scott), which did not sit well with Clement Johnson (Richard T. Jones), Nona's former boyfriend and the station's traffic cop. Eventually Nona and Clem got back together, then broke up, and by the series end, Nona got back together again with Lowery. Hector Villaneuva (Adam Rodriguez) was a young rookie cop who was tutored by the rest of the officers how to do his job the best be could.