Police have tentatively identified the body of Emilliano Terry, but the medical examiner said DNA tests will be required for a positive ID.
The boy's mother, Camilia Terry, 20, was arrested Monday after his body was found in trash bags at a waste processing site, police said. She initially had reported him missing from a park the day before.
Investigators said the mother's story changed, leading them to suspect that she was involved in his death. FBI agents stopped a garbage truck while searching the neighborhood and went to the trash processing location.
No charges have been filed, and no details about the boy's death have been released.
Terry was in jail Tuesday and couldn't be reached for comment. Her phone voice mailbox was full and couldn't accept messages, and it was unclear if she had retained a lawyer.
Terry had been in county custody from 2009, when she was 17, until February, when she was 19. Young people can stay in county custody after they turn 18 if troubled circumstances warrant, Cuyahoga County Department of Children and Family Services spokeswoman Mary Louise Madigan said.
Terry was a foster child and remains in touch with her foster parents, Madigan said. Her two other children, sons, one 5 years old and the other 5 months old, are in county custody.
The (Cleveland) Plain Dealer reported that the mother had posted to several online sites used by singers and songwriters.
In one post, she sings a haunting refrain about being in pain from losing someone. One of the lines is, "I had a dream that someone I knew was going to die."
Several videos posted online seem to contain biographical details of her life in foster care, being a single mom, feeling alone and being stressed out.