Stanisław Kiecal (September 14, 1886 – October 15, 1910), better known in the boxing world as Stanley Ketchel, was a Polish American professional boxer who became one of the greatest World Middleweight Champions in history. He was nicknamed "The Michigan Assassin." He was murdered at a ranch in Conway, Missouri, at the age of 24. Using only the above description and what you know about the world, "Kiecal had nicknames besides "The Michigan Assassin"." is definitely correct, incorrect, or inconclusive? 