Radical historians have their guilty pleasures too, and Michael J.Schaack's Anarchy and anarchists has to rank right up there in my top ten list. Subtitled "A history of the Red terror and the social revolution in America and Europe. Communism, socialism, and nihilism in doctrine and in deed. The Chicago Haymarket conspiracy, and the detection and trial of the conspirators," you're not going to have any trouble figuring out on which side he's coming down. Of course, the author was also a member of the police force, so. . .
The link above is to an electronic copy in the Gallica collection. Use the "télécharger" button to assemble a complete pdf file or download it in chapters from Northwestern's "Homicide in Chicago" pages, which also feature a nice selection of related newspaper articles, photographs and illustrations.