Riverside County Sheriff's Detective John Powers tells KFI-AM radio Thursday that Pam Ragland found the body matching the description of 11-year-old Terry Smith. A 16-year-old half brother was later arrested on suspicion of murder.
Sheriff's spokesman Albert Martinez also confirmed Ragland's involvement for The Associated Press.
Powers says Ragland called a tip line about her vision, and was invited to join the search.
He says Ragland and her children came to the house without knowing it was the boy's, walked on to the property and right to the partially buried body.
Powers says he searched the area previously himself without seeing it.
Terry Smith was reported missing Sunday, prompting a massive search. On Wednesday, authorities announced they had found a body matching Terry Jr.'s description in a shallow grave under a tree behind his mother's house.
The boy's half brother could be charged as early as Friday, a person familiar with the investigation told The Associated Press. The person requested anonymity because they are not authorized to speak publicly about the ongoing investigation.