KANSAS CITY, Kan. (AP) — A former Kansas sheriff has pleaded guilty to letting his son possess firearms and ammunition even though the younger man was convicted felon.

The U.S. Attorney’s office said 70-year-old Barry Walker, of Mound City, entered the plea to the federal firearms violation on Monday. His son, 47-year-old Pleasanton resident Jeffrey Nicholas, pleaded guilty to possessing firearms and ammunition after a felony conviction.

Walker is the former sheriff of Linn County and the owner of Big Bear’s Gifts & Pawn Shop in Pleasanton. Nicholas has a felony drug conviction from Nevada and worked for his father at the shop.

Prosecutors said federal agents warned Walker to stop letting his son sell guns at the store. But undercover agents later bought firearms from Nicholas at various times.