Updated: January 30, 2014 at 5:34 pm
GAITHERSBURG, Md. (AP) — An off-duty Montgomery County police officer shot and killed his son after the younger man stabbed his mother at their home, police said Thursday.
The officer fired at his 25-year-old son on Wednesday night after he attacked his mother with a sharp object in an upstairs bedroom of the family's Gaithersburg home, said Capt. Jim Daly, a police spokesman. The woman was critically injured and later died at a hospital.
"It's a tragic situation, unimaginable," Daly said.
Police say they are still investigating how the violence unfolded, though investigators believe the officer shot his son after coming to his wife's aid and then called 911.
Daly said the officer, identified as James Stirkens, is a patrol sergeant and 27-year veteran of the department. The officer has been placed on administrative leave, which is standard in cases of officer-involved shootings.
The police commander of the district where Stirkens works did not immediately return a call seeking comment Thursday. A phone listing for the family was not set up to take voicemail messages.
The reason for the fight was not immediately known, but police say the officer at some point heard a commotion involving his wife and son, Christopher Stirkens. Denise Stirkens, 53, was too critically injured to be interviewed by police.
The sergeant was interviewed Wednesday night, and no charges have been filed.
"The challenge we have here is there were only three people in the house," Daly said. "We don't have anyone else."
Gaithersburg is a suburb of Washington, D.C., located about 20 miles northwest of downtown.