KENNEWICK, Wash. (AP) — A jury returned a guilty verdict against a Tri-Cities woman for shooting and killing her best friend after finding her in bed with her fiancé two years ago.

The Benton County Superior Court jury on Monday found Amy Sue Brown of Prosser guilty of second-degree murder after deliberating for less than three hours.

According to court documents, Amy Brown, her fiancé Brandon, her friend Amanda Hill and Hill’s boyfriend Ben were celebrating Brown’s birthday in a camper next to her home when the shooting happened. Brown says her friend left the camper to use the bathroom in the house, but when she didn’t return after 20 minutes, Brown went into the house to check on her. That when she Hill in bed with her boyfriend.

Brown claimed she grabbed her gun after a being attacked by Hill during a confrontation outside the home.