About the murder/disappearance:
From
http://www.coreyrecko.com(site for book
Murder on the White Sands: The Disappearance of Albert and Henry Fountain):
It was the end of January 1896 when the Grand Jury adjourned in the town of Lincoln, territory of New Mexico. Colonel Albert Jennings Fountain had just worked to bring indictments against several men in order to combat the cattle rustling that ran rampant in the territory. His work finished, Fountain, with his eight-year-old son Henry, left Lincoln. The pair headed southwest, towards their Mesilla home. The journey, some 150 miles, would take three days. It was a journey the father and son would not complete, for on the 3rd day they disappeared near the White Sands, an area known for mysterious disappearances. What became of them remains New Mexico's greatest murder mystery.
and a more biased take from wikipedia:
On 1 February 1896, Fountain and his eight-year-old son Henry disappeared near the White Sands on the way to their home in Mesilla, near Las Cruces, New Mexico. All that was discovered were Fountain’s buckboard, several empty cartridge casings, his cravat and papers, and two pools of blood. The only sign of Henry was a blood drenched handkerchief with two powder-blackened coins, the handkerchief still carefully knotted in one corner. Missing were the victim's bodies, a blanket, a quilt, and Fountain's Winchester rifle.