CHICAGO (CBS) — A man has been released without charges, after he shot and wounded his girlfriend’s ex-husband when the man stormed into her Far South Side home.

The 49-year-old ex-husband walked up to the woman’s home in the 10300 block of South Emerald Avenue in the Washington Heights neighborhood around 4:30 a.m. Monday, police said. He first banged at the door, but then kicked it down and forced his way in.

The ex-wife and her boyfriend were sleeping inside, but were awakened by the noise, and the boyfriend shot the man, police said. It is not known if the boyfriend knew it the man was his girlfriend’s ex-husband, or thought he was just an intruder.

The ex-husband was taken in critical condition to Advocate Christ Medical Center in Oak Lawn with a gunshot wound to the abdomen, police said.

The boyfriend was initially taken into custody, but he was released without being charged, police News Affairs Officer Michael Sullivan.

The Sun-Times Media Wire contributed to this report.