A man stabbed his girlfriend in the head during an argument Tuesday on a Green Line train in the Loop, police said.
They were riding a train about 9:16 p.m. in the first block of North Wabash Avenue when their argument turned physical and the 59-year-old man attacked the woman with a knife, Chicago police said.
She was taken to Northwestern Memorial Hospital in fair condition, police said. The man was arrested and taken to Mercy Hospital and Medical Center for scratches suffered during the confrontation.
He was charged with one misdemeanor count of domestic battery, police said.
Area Three detectives are investigating.