The Sinister Pig by Tony Hillerman

Sergeant Jim Chee of the Navajo Tribal Police is troubled by the nameless corpse discovered just inside his jurisdiction, at the edge of the Jicarilla Apache natural gas field. More troubling still is the FBI's insistence that the Bureau take over the case, calling the unidentifiedvictim's death a "hunting accident." But if a hunter was involved, Chee knows the prey was intentionally human.