premise: Nathan Wesley Everest (December 29, 1890 in Newberg, Oregon — November 11, 1919 in Centralia, Washington) was an American member of the Industrial Workers of the World (IWW) and a World War I era veteran. He was lynched during the Centralia Massacre after killing Dale Hubbard in what the union called self-defense, though the American Legion called it murder.
hypothesis: Nathan Wesley Everest was lynched because he committed murder. 
reason: According to the context, Nathan Wesley Everest was lynched because he killed Dale Hubbard.