LIBERTY COUNTY, Texas -

The search for a missing 2-year-old boy believed to have wandered into a wooded area in Liberty County turned into a recovery mission Thursday, officials said.

An Amber Alert was issued for Devon Davis on Tuesday. Liberty County sheriff's deputies said Devon wandered off while his mother and 1-year-old sibling were napping at the their new home in the Sam Houston Lake Estates area near Tarkington about 3:30 p.m. She found the door open and the child gone.

The Davis family has only lived in their home a week. They moved to the area from Virginia.

Officials and volunteers from Liberty County and surrounding areas were searching by air, land and water. On Thursday morning, Liberty County officials said the search is now a recovery, meaning that they don't expect to find the boy alive.

Capt. Rex Evans said he had to have a difficult talk with Devon's parents Thursday morning.

"There is a negative end to this that you kind of have to prepare yourself for," said Evans.

The Houston Police dive team and Texas EquuSearch joined the search Wednesday morning. Evans said waterways near the home have been searched and nothing was found. More areas of the waterways were searched on Thursday.

Texas EquuSearch has used sonar devices to look for Devon. Devon Davis

"The problem with doing the sonar is there's just so much debris underneath the water," Texas EquuSearch founder Tim Miller said. "You get a false image and you have to go back over it two or three times to determine what it is."

Miller said the terrain is difficult to search because of the woods, water, and wildlife. He said his volunteers have seen alligators, snakes, and wild boars. Immigration and Customs Enforcement agents armed with rifles are standing on the banks while divers search the water to protect them from alligators.

Detectives said they have searched every building in a one-mile radius of the home without luck. The search was widened on Thursday.

Dozens of dogs were used to search the area for any signs of the boy.

Investigators have searched Devon's home looking for clues, too.

Evans said Devon's parents are heartbroken and have been cooperating in the investigation. Investigators said Devon's mother took a short nap because she was simply exhausted, and Devon's father was at work when his son disappeared.

Investigators said they do not suspect foul play. The FBI did have a personality expert on hand when a formal statement was taken from the parents as part of the normal investigative process.

Detectives are investigating the possibility that Devon let himself out of the home. The window in his second-story bedroom was open when he disappeared, but Evans said it has been ruled out that he got out of the home through it.

Miller said Devon's parents asked to help with the search but weren't allowed because no one knows what will be found.

"If I was honest with myself right now, I'd say we're in recovery. I think that everybody involved agrees with that. But we're holding onto that miracle," added Miller. "We hope for that miracle that I truly believe is not going to happen."

Crews said they will continue to search until they find Devon to help give the family closure.

Officials said there is no more need for civilian volunteers. However, water donations are needed because conditions are so harsh.

Devon is 30 inches tall and weighs 40 pounds with red hair and blue eyes. He was last seen wearing a red and gray jersey T-shirt, jeans and Spiderman tennis shoes.

Anyone with information regarding Devon's whereabouts is asked to call the Liberty County Sheriff's Office at 936-336-4500.