FARMINGTON, Mo. (AP) — An eastern Missouri sheriff says a 14-year-old used a steak knife to fatally stab a woman who was fighting with his mother.

St. Francois County Sheriff Dan Bullock says 35-year-old Alicia Morris died at a hospital after the altercation about 5 p.m. Monday.

Authorities say Morris had accidentally driven off of the road in Farmington and walked with her boyfriend to a nearby home to borrow a chain to pull the vehicle from a ditch.

The teenage boy went with the couple to help them free the car and was dropped off back at home. Authorities say that’s when the women argued, and the boy stabbed Morris once in the back.

It was not immediately clear if the teenager has been charged, though Bullock said he was in juvenile custody.