The investigation began Tuesday when staff at Mercy Hospital grew suspicious of the child's injuries. The medical staff called police.
The mother, whose name was withheld, brought her unresponsive 2-year-old son to the hospital and claimed he choked on a potato chip.
Investigators determined that the boy had actually been hurt in a fall 10 days earlier at a home on the 400 block of Whitlock Street. The mother and her boyfriend sought "alternative medical care at a private residence" instead of taking the boy to a hospital, according to police.
The alternative medical care is also under investigation, now.
The child's 5-year-old sibling was taken into protective custody.
Anyone with information on this case is asked to call Detective Rex Davenport at (661) 326-3559.