Burke's Law - Season 2 Episode 21 : Who Killed the Fat Cat? 1966

A big business wheeler-dealer, formerly part of a carny consortium, meets his end after injesting cyanide - but he didn't eat or drink anything that had been tampered with. The suspects all formerly worked with the victim in the carnival racket and are now heads of powerful companies: a health club president, a fitness tonic manufacturer, the producer of fancy lingerie and the head of a think tank. Only one of the old gang hasn't made it big and now runs a local merry-go-round. When Les almost dies of cyanide as well, Burke discovers the murder weapon in an unlikely spot. He then turns the tables on one of the carny con artists and nails the killer.