Swanny Swanson was the nephew of Commodore Otis Swanson and murderer in Last Salute To The Commodore.
Swanny killed his uncle, the Commodore, whilst his cousin, Joanna Clay, was in a drunken state nearby and angry with her father. This was an attempt to have the Commodore dead and his daughter framed and unable to inherit, meaning that Swanson Boatyard and all of Otis Swanson's wealth would go to Swanny. When Lieutenant Columbo began investigating the Commodore's murder, Otis was open to helping, but grew concerned when he realised that the lieutenant was suspecting Joanna's husband, Charles Clay, instead of her as she had intended. To cast guilt back on Joanna, Swanny killed Charlie Clay. He agreed to help demonstrate how someone wearing the Commodore's clothes could have faked him being alive for Columbo and was around for the lieutenant's parlour room explanation. Eventually, Columbo caught him for the Commodore's murder by demonstrating how he must've killed his uncle duo to how he knew that the Commodore's watch was broken and couldn't be ticking when Columbo held a fixed version up to his ear.
Swanny Swanson was played by Fred Draper.