The Buttercup Killer Police Woman : Season 4 Episode 6

When a Greek shop owner's murdered, Crowley's surprised to learn robbery wasn't the motive. The victim was petrified with terror even before he was killed . The killer donnun's habit and walks with a limp. The only clue; a buttercup flower dropped next to the victim.The team realisesthe clues are designed to remind them off someone wronged terribly, and are now to pay the price.