The Politest of Murders: Only the Rude

Who would ever suspect this sweet little waitress of poisoning people? Certainly not the grouchy old detective on the case, who she often serves at the restaurant. Only the rudest of people are poisoned, of course, as a public service, you see. Who would think the cute little snails in the fish tank at the restaurant produce the deadliest neurotoxin on the planet or that the saliva of the Emerald Trigger fish in the tank is the only antidote? Enjoy your meal, but be polite.