 His official statement indicates the latter, in reference to an assault perpetrated by a couple of Iron Policemen.The brutality of the Coal and Iron Police forms the background to some sections in Dos Passos's "U.S.A." trilogy, focusing on miners' struggles and strikes in Pennsylvania.The Coal and Iron Police also feature in the Sherlock Holmes novel, "The Valley of Fear", which is based loosely on the breaking of the Molly Maguires.