A two-year-old boy vanished from a campground in Arizona Sunday after his soon-to-be adoptive mother tucked him into his sleeping bag in a tent that the family was sharing.
Authorities in Rimrock, Ariz., are in the third day of their search for Syler Newton, and are trying to determine whether the little boy wandered off on his own or whether he was the subject of a custody dispute.
"So far we don't have any reports that Syler was taken from the campsite," said Yavapai Sheriff's Office spokesman Dwight D'Evelyn. "That's been the thing that keeps us believing that he wandered away from the tent."
Syler is described as having brown hair, green eyes and weighing just 20 pounds. He was last seen wearing only a diaper.
According to police, Syler was last seen around 12:30 a.m. on Sunday by his custodial mother, 37-year-old Christina Priem, at the Beaver Creek Campground, which is about 50 miles south of Flagstaff.
According to police, Priem said the boy had been sleeping next to her, her mother and Priem's 12-year-old daughter before he disappeared. Priem's 14-year-old son and his friend were sleeping in an adjacent tent. The family had been camping at the site since Friday evening.
According to investigators, Priem said she discovered that Syler was missing around 1:45 a.m. Police say that the first call to 911 was placed just 15 minutes later by one of Priem's family members but the call was lost because of a bad connection. Deputies eventually arrived around 3 a.m. to begin searching for Syler.
D'Evelyn said that Priem and her mother, Nancy Collins, have both taken polygraph tests and have been cooperative with police. Both Priem's and and Collins' cars were taken by detectives to be examined, said D'Evelyn.
ABC News was unable to reach either Priem or Collins.
A search of public records shows that Priem has a criminal history, including a 2007 charge of falsely reporting a crime to police and a prescription drug violation in 2004.
Syler's biological mother, who lives out of state and whose name has not been released, has also been interviewed by police, according to D'Evelyn.
Priem's sister, Angela Godinez, told CBS' Phoenix affiliate KPHO that Syler's biological mother "doesn't really have a connection with him," adding that she had "signed over papers and everything."
Godinez added that Syler's soon-to-be adoptive family is "preparing for the worst."
The search is continuing and the FBI has been called in to aid in the investigation. The 25 campers who were in the area when Syler was reported missing have all cooperated with officials say authorities. Detectives are also reviewing the reservation list for the campground during the time Syler was there.
"We've expanded the search to encompass a larger area that spans several miles," said D'Evelyn. "We're using bloodhounds and flyovers and a lot of ground units."
D'Evelyn estimated that about 40 searchers were on the ground combing the campsite. It is rough terrain filled with rocks and trees, as well as a flowing creek.
"We had a rain blast yesterday that came through, that kind of helped in a way because it cooled everything off," said D'Evelyn. "But for a two-year-old, it's been fairly warm overall and the overall concern is really dehydration."