WAUKEGAN, Ill. — An off-duty Waukegan police officer shot and killed her husband Sunday night, authorities said.

At around 8 p.m., officers responded to a home in the 2000 block of North Avenue on the report of a shooting. Officers discovered a man in his 30s who had been shot and a woman, later identified as a 19-year veteran of Waukegan police, with him.

The man was transported to an area hospital where he was pronounced dead. The pair were husband and wife, police said, and the officer’s service pistol was used.

Police said they believe that a domestic incident occurred, which “resulted in the officer shooting her husband.”

The officer has been placed on administrative leave, pending an investigation by Illinois State Police. Waukegan police said the officer is cooperating with authorities.