Through searching newspapers in New Mexico looking for collaborative information regarding the legend of the death of William Alexander and his son, which I had been told was by cattlemen who did not like sheep herders, I located several articles which I have attached links to from the Library of Congress' web site.
Anyways, William Alexander was accused of sexually assaulting a minor. A warrant was issued, he fought authorities and shot the sheriff while attempting to escape his home and was subsequently injured during apprehension. When released from the hospital he was being escorted back to Newkirk NM and shot by the minor victim's father as William exited the train.
Far less dramatic than the legend.