Dominic West will forever be McNulty from The Wire, which makes his turn as British serial killer Fred West even more fascinating in this weekend's Appropriate Adult, a two-part mini-series airing on Sundance. He's not the only actor to take on iconic roles as both police officer and murderer, though — in fact, he's in really good company. But which role is better? More interesting? More challenging? More enduring? Join us as we examine seven of the actors who've played both cop and killer, and argue with us as we analyze which they did better.