L. J.

Harry Orchard implicated Western Federation of Miners executive board member Jack Simpkins in the murder of Steunenberg. Simpkins disappeared after Haywood and the others were arrested and he remained a mysterious figure. Despite the efforts of both the Pinkerton and Thiel detective agencies and a $2,000 reward from the State of Idaho, he was never found. Simpkins' disappearance was the subject of numerous rumors:

"Simpkins was dead, killed by the WFM to ensure he never informed on his co-conspirators; Simpkins had found sanctuary in Australia or Singapore; Simpkins was a Pinkerton plant, an agent provocateur sent my McParland to trigger the Steunenberg assassination as a means to exterminate the WFM's leaders." J. Anthony Lukas, Big Trouble: A Murder in a Small Western Town Sets Off a Struggle for the Soul of America 293 (1998).