Ein Truminn attained the rank of lieutenant and served as a bridge officer aboard the Executor-class Star Dreadnought Executor, where he developed a rivalry with fellow officer Lieutenant Tanith Sorn.
Shortly after the Battle of Hoth in 3 ABY, Sorn was sent to the Executor's hangar bay to greet bounty hunters who had been summoned to the ship by Darth Vader. The Class 720 freighter Onderian Raptor landed in the hangar and an armored individual emerged from it, and told Truminn that his name was Bail Antilles and that he and his crew were bounty hunters. However, the Executor's bridge commander detected a Rebel Alliance code that was being broadcast from the freighter, and ordered Truminn and a group of crewmen to apprehend Antilles and his crew. However, the Raptor's crew opened fire on the Imperial officers and Antilles shot Truminn in the chest at point blank range, crtically injuring him.