Question: Mike Gibbons was an American boxer who claimed the Middleweight Champion of the World status following what Polish American professional boxer's murder?
Sentence (from "Stanley Ketchel"): 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.
Relevant evidence: Yes