July 1999. Carlsbad Caverns National Park in New Mexico. David Coughlin and Raffi Kodikian were best friends. Both from Boston, though David was preparing to move to California. Raffi joined him on a cross country trip which would take them about five days. But a decision to stop in Rattlesnake Canyon in Carlsbad Caverns National Park would prove to be too much. Though they were cautioned about the desert and being prepared, they thought that one night wouldn't be a big deal. Days later when a park ranger located their camp, he discovered only Raffi had survived. David was dead and Raffi immediately said that he was responsible. But was this a mercy killing as he had claimed? Or was there a motive for murder?