We spent years with Omar. In his way, he was principled, committed to hustling those who hustled others. (“A man got to have a code,” he said once.) His moral compass so endeared him to viewers that he long outlived the seven-episode arc his creators had originally planned for him. More than any other death on “The Wire,” Omar’s made us know the agony of caring for a murder victim—even one who, by all rights, had it coming. For a moment, we knew how it felt to have someone close to us die, and to wait in vain for someone to give a damn.