Elementary Season 4 Episode 9 "Murder Ex Machina"
Mason: So why do you care? I'm just saying - he was a bad guy, now he's dead. We should go see a movie or something.
Joan: The people who killed him also killed his bodyguard and the valet who was getting his car.
Sherlock: And even if there were no innocent victims, no murder should go unsolved, and no murderer should walk free. To think otherwise is to descend into a pit of moral relativism.














