ACKLEY, Iowa — Police say an Iowa man and his girlfriend tortured the man’s 8-year-old son for months by locking him in a basement enclosure, withholding food and making him endure dog bites.

The Hardin County Attorney’s Office said Wednesday that kidnapping charges had been filed against 39-year-old Traci Lynn Tyler and 30-year-old Alex Craig Shadlow, both of Ackley.

An arrest affidavit says the abuse occurred between July and September 2017. Investigators allege the boy was locked for at least nine hours a day in an enclosed 6-foot-square space under the basement stairs, where he slept on concrete with no bedding and had no access to a bathroom.

Police say Tyler also urged her dog to attack the boy, which left scars on his back and limbs.

Authorities say the boy’s school alerted investigators to the abuse.

The couple’s attorneys didn’t return phone messages Thursday.