HARRISONVILLE, Mo. - The Cass County Sheriff says the 5-year-old boy's body was found at the bottom of a pond located near the house.
Divers with the Missouri Highway Patrol water division used sonar equipment to detect the boy's body in a friend's pond.
Investigators aren't sure how long the child was in the pond. They said it's possible the child fell in earlier in the day.
"It's our assumption he's been there since shortly before we arrived on the scene and starting for him at that point," Lt. J. Kevin Tieman II with the Cass County Sheriff's Office said.
Tony Eugene "Gene" Cory-Ferguson had autism and walked away from his grandparent's home south of Harrisonville off 7 Highway around 11:45 a.m.
Capt. Mitch Phillips with the Cass County Sheriff's Department said that an air conditioning repairman was in the house and the front door was open. He said Gene's mom believes her son probably walked out of the front door.
Police said he had done this in the past, but he had always been found quickly.
Authorities searched for the young boy for more than six hours.
The sheriff's office said they used every available resource to try and find Cory-Ferguson.
"It's a hot day in the summer. They worked as hard as they could, diligently as they could, trying to locate this boy and unfortunately it didn't come to a happy result today," Tieman said.
The boy's body is at the Jackson County Medical Examiner's office awaiting autopsy.