Suspense (1949): "The Mallet" (12 Dec. 1950; Season 3, Episode 16)

From IMDb; Storyline: ""A bellicose huckster travels the fairs of England shilling his magic elixir. The "doctor," as he's called, is befriended by a couple in a local tavern who proceed to get him intoxicated. The husband tells Dr. Potteton that he'd love to kill his greedy brother and asks him how he could go about it without being caught. The sideshow charlatan launches into a elaborate step by step instructions on how to get away with murder."". - Written by Jay Phelps. Trivia: Walter Slezak's TV debut.