(CBS/AP) MENIFEE, Calif. - The suspect in the killing of Terry Dewayne Smith Jr., an 11-year-old California boy with autism, is his teenage half brother, a person close to the investigation said Thursday.
The person who was not authorized to speak publicly about the case told The Associated Press that charges could be filed as soon as Friday against Terry Dewayne Smith Jr.'s 16-year-old half brother, whose name has not been released.
Police found a body matching Terry's description Wednesday in a shallow grave behind the boy's house. He was reported missing Sunday and authorities have said the half brother was the last person to see the boy alive.
Authorities announced late Wednesday that a body matching Terry's description had been found and a 16-year-old family member was arrested on suspicion of murder.
The boy's mother and other family members were also taken in for questioning but released, said Riverside County sheriff's Deputy Albert Martinez.
Menifee Police Chief John Hill said at a news conference Wednesday that the death was the result of "a domestic issue" at the house.
Police responded to a tip about the body early Wednesday, said Hill. Televised news reports showed sheriff's investigators concentrating on what appeared to be a small hole by a tree about 75 feet from the house, which sits in a rambling, weedy lot off a remote road in Menifee, a Riverside County community about 70 miles southeast of Los Angeles.
Though Terry was last seen Saturday night, his mother, Shawna Smith, said she did not realize he was missing and report it until Sunday morning.
Hundreds of volunteers had helped authorities in the search alongside bloodhounds, horses and helicopters in triple-digit desert heat. But the volunteers were told to stop Tuesday night because they were getting stranded in the desert and causing other problems.
A posting on a Facebook page devoted to the search said Terry's family worried he might have wandered off without food, water or special medication.
But investigators had never ruled out the possibility of foul play, deputy Martinez said.