Storm Riders by Ed Gorman
U.S. Marshal Earle Conlon has been ordered to offer amnesty to the most wanted man in the country -- Billy Pecos -- in exchange for bringing the New Mexican range war to an end. But when Billy is caught at the scene of a brutal murder, the territory prepares for a lynching -- and Conlon is the only man willing to protect the disreputable outlaw for the chance of catching the real killer...