http://www.amazon.com/His-Name-Still-Mudd-Alexander/dp/1577470192
From the blurb:
Arguing forcefully and with the weight of great evidence, Dr. Edward Steers proves how mistaken modern efforts to exonerate Mudd are. Mudd knew Booth well; he had entertained him as an overnight guest just months prior to the assassination. Mudd even plotted with Booth to capture Lincoln, and introduced Booth to key conspirators.
The claim that a man who knew Booth well, had been part of an earlier conspiracy against Lincoln, let a supposed "stranger" into his house in the middle of the night and got close enough to him to treat his injuries sustained earlier in the murder of the President failed to recognize him because of a theatrical disguise is as preposterous a fiction as the the idea that a squad of terrorists armed with mortars and RPG's showed up at the US mission as a spontaneous response to a YouTube video to murder the US Ambassador to Libya.
Mudd was guilty as hell, and his descendants should give it up. They're a laughingstock.