WEST BLOOMFIELD, Mich. (AP) — The parents of a teenager wounded during a mass shooting at Oxford High School in Michigan are suing the shop that sold the handgun used to kill four students and injure six other people.

The federal complaint filed Tuesday on behalf of Matthew and Mary Mueller accuses Acme Shooting Goods LLC of negligently or unlawfully supplying the gun through a straw sale.

Authorities have said James Crumbley bought the 9 mm semiautomatic handgun used in the Nov. 30 shooting as an early Christmas gift for his 15-year-old son Ethan.

An employee at the gun shop in Lapeer declined to comment Wednesday on the lawsuit.