An Illinois mother and her boyfriend are behind bars after police say they subjected her 11-year-old son to years of horrifying abuse that included beatings, humiliation and forcing the child to repeatedly write that nobody loved him.

Pricilla P. Marshall, 34, and Cody R. Marion, 35, were arrested after authorities say the boy was found wandering outside a business wearing only a diaper and covered in injuries.

The Fox Lake Police Department said the disturbing case came to light around 9:30 a.m. Friday when a business owner in the area of Nippersink Boulevard and Grand Avenue discovered the child and called police.

Officers arrived to find the boy with blood on his face and numerous welts, bruises and scratches across his body, according to police. The child was immediately taken to a hospital for treatment.

Investigators then went to the boy’s home, where they located Marshall. Authorities said several other children lived in the residence — including two toddlers ages 1 and 2 and two older boys who were at school at the time — but none of them showed signs of abuse.

What detectives say they uncovered next painted a grim picture of years of cruelty directed at just one child.

After conducting forensic interviews with the children, investigators concluded that Marshall and Marion had allegedly abused the boy for years.

Police say the punishment went far beyond ordinary discipline.

According to authorities, Marshall and Marion allegedly beat the boy with household objects and poured dish soap into his mouth and ears.

Prosecutors revealed additional disturbing details during a weekend court hearing, according to the Lake & McHenry County Scanner.

Marshall allegedly beat the boy with extension cords, metal spatulas and spoons, and sometimes punched him in the face.

Investigators say the mother would often force the child to remove his clothing before beating him so the punishment would hurt more.

Prosecutors also allege Marshall threatened to stab the boy “33 times” and even forced his older brother to physically assault him.

But the abuse was not only physical.

Authorities say Marshall also subjected the boy to cruel psychological torment.

According to prosecutors, she forced him to kneel on uneven floorboards while repeatedly writing sentences in a notebook declaring that he was unloved.

The messages included phrases such as: “You’re not a loved child, everybody hates you.”

Investigators say the humiliation extended to meals as well.

While the other children were reportedly given fast food from McDonald’s or Pizza Hut, the boy was forced to eat canned food or ravioli.

Police emphasized that none of the other children in the home appeared to have been harmed during the alleged abuse.

After completing interviews and gathering evidence, officers arrested Marshall and Marion and transported them to the Lake County Jail.

Both suspects are now facing charges including aggravated battery, endangering the life of a child and two counts of domestic battery.