Officials labeled the parents of a missing 2-year-old boy suspects in the case on Jan. 25.
Fox News reports the 25-year-old mother, Jessica Mitchell of Idaho, reported her son missing from a campsite in July 2015.
She told police that she and the boy’s father, DeOrr Kunz Sr., went exploring and left their son with his great-grandfather. Meanwhile, the great-grandfather thought the boy was with his parents.
Lemhi County Sheriff Lynn Bowerman said the parents had been "less than truthful" about their son's disappearance.
Frank Vilt, a former investigator who worked with Mitchell and Kunz, backed out of the case after he stopped trusting the parents, East Idaho News reports.
“I told both of you that if I felt that you were not telling the truth, stalling me, or otherwise misleading me, that I would with draw from the investigation,” Vilt wrote in a Sept. 25, 2015, letter to Mitchell and Kunz which was later released to the public. "In my professional opinion, both of you lied and misrepresented the true facts that could solve the mystery of your missing son."
According to the letter, Vilt wanted to advertise a $20,000 reward to help find the couple's son, but the parents refused it, leaving him "perplexed."
Vilt accused Mitchell and Kunz of trying to cover up crimes they might have committed, and suggested the couple cooperate with authorities.
“How can [you] live with yourselves?” he wrote. "Sooner or later, the truth will come out."
Another investigator, Philip Klein, picked up the case after Vilt left.
Bowerman believes the parents know where their son is and whether he is dead or alive.
"We don't have any evidence that somebody kidnapped this child," Bowerman said.
The sheriff explained that the area where the parents said the child was abducted is "steep and rugged." While vehicles can access the site, "the road is extremely rough," he said.
Moreover, no other campers appear to have been present when the child reportedly went missing.
No warrants have been issued nor arrests made.