Four-year-old Demond Reed had been missing since Wednesday. He was staying with relatives in Minneapolis.
At first, police thought a family friend may have taken the boy and headed to Chicago. But Reed's body was found Sunday in the house where he had been staying.
His grandmother can't understand why anyone would hurt the little boy.
"Now all I have is this picture, this memory of him with his smile. God has him and he's a child of God. He's in God's care," said Charmon Brown, grandmother.
Police say they have a female relative in custody. So far, no charges have been filed.