The series invites viewers to form their own judgments regarding Mackey's volatile behavior, which includes killing an undercover cop in the electrifying pilot episode. While each episode stands alone as groundbreaking drama, the arc of the series incorporates Aceveda's campaign to end Mackey's career; the self-loathing of a homosexual rookie (Michael Jace) whose partner (Catherine Dent) is Mackey's occasional mistress; a straight-laced detective (Jay Karnes) yearning for respect; Mackey's compassionate attempt to rehabilitate a crack whore (Jamie Brown, giving the season's finest guest performance); the autism of Mackey's young son and the recklessness of his closest partner (Walton Goggins); and the vigilant stoicism of Det. Wyms (CCH Pounder), who's as sensibly upright as Mackey is corrupted.

Teeming with gang-bangers, perverts, rapists, and killers, The Shield is unabashedly adult; even liberal viewers may flinch at plots involving child pornography and serial murder. Chiklis deservedly won an Emmy for maintaining the series' delicate morality; Mackey's a hero squirming in his own ethical quicksand. This daring edginess makes The Shield unique, and generous DVD supplements explore Ryan's creative impulse. Two featurettes offer behind-the-scenes overviews, while the all-episode commentaries allow extensive insight from every member of the series' principal cast and crew. Audition tapes prove that the cast was primed for ensemble excellence, and deleted scenes further demonstrate the series' challenging ambiguity. The Shield is excellent TV for those who can grasp its complexities; all others beware. --Jeff Shannon