In today's family configuration, the term "latch-key" children may have a different meaning from past years.
According to this article "Any parents who leave their children age 13 or younger home alone may be guilty of neglect under Illinois state law.
https://www.illinoispolicy.org/leave-your-13-year-old-home-alone-police-can-take-him-into-custody-under-illinois-law/