 The title of this episode seemingly refers to the arrest of Bird for the murder of William Gant, the major event of the episode.As the wire taps are killed by the payphone removal, "One Arrest"—that of Kevin Johnston, the runner—is also the sum total of progress the unit made from information gathered from the wire.Another interpretation of the title is that it refers to Rawls's demand that Santangelo close at least one case; for a homicide case to be considered "closed" only requires that a suspect be arrested and charged.