ST. PAUL, Minn. (AP) - The widow of a slain Minnesota Air National Guard member is charged along with another man in her husband's killing.

Twenty-four-year-old Heather Horst of St. Paul is charged with second-degree murder and conspiracy to commit a felony in the shooting death of her husband, Staff Sgt. Brandon Horst.

Photo by: HeatherHeatherHeather, flickr

Also charged is 25-year-old Aaron Allen of South St. Paul. Allen is engaged to Brandon Horst's stepsister.

According to charges, Heather Horst called 911 early on Aug. 5. Authorities found Brandon Horst in the bedroom with a gunshot wound to his head. A 9 mm casing was on the bed.

Heather Horst told police she and her husband had been arguing about his idea of having an open relationship. She denied being involved in her husband's killing.