Flint-area authorities say a man fighting with his girlfriend struck her 9-year-old brother with his car, critically injuring the boy.
Mlive.com says the man fled from the scene in Genesee County's Mount Morris Township on Wednesday morning. Township police Chief Scott McKenna says investigators tracked the man to a home in Flint and took him into custody.
McKenna says the man and his girlfriend were arguing, and the boy went out to the road to intervene.
The 9-year-old's condition was described as "extremely critical."