The man, whose name and age were not released Tuesday, allegedly used a rearview mirror from his car to strike his 27-year-old girlfriend in the back of the head during a Monday argument, investigators said.
The assault occurred around 2:15 p.m. Monday in the 600 block of Old Gadsden Highway.
An officer who responded to the scene noticed that the woman had a laceration on her forehead and swelling on the back of her head.
Investigators had not made an arrest in the case by Tuesday afternoon.
Contact Star Staff Writer Cameron Steele at 256-235-3562.