Premise: 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.
Hypothesis: Stanisław Kiecal retired from professional boxing in 1911.