A Pennsylvania couple was charged with homicide on Monday for allegedly killing a 12-year-old boy by beating him, starving him, and locking him in a room caked in his own excrement for several years.

According to detectives, the boy, Maxwell Schollenberger, was never enrolled in school, had not received medical care for a decade, and was rarely seen even by his own siblings who lived at the same residence in Anville, Pennsylvania, PennLive reported.

Investigators said that some of the couple’s family and friends reported “not seeing the victim in quite some time and some were not even aware of his existence.”

The boy’s biological father, Scott Schollenberger Jr., 42, and his fiancée, Kimberly Maurer, 35, were arrested in connection with the boy’s death roughly three months after his emaciated and badly injured body was found inside the home.

A neighbor had reportedly called police about the child, and that’s when authorities found out that he even existed, WGAL-TV reported.

When detectives entered the room on May 26, here’s what they found, according to PennLive:

They said the boy was completely naked and his feces-covered body was sprawled across a bed that was covered in human waste, in a room that was caked with such waste that was so old it had turned moldy. “Claw marks appeared in the child victim’s sheets,” they wrote. “Such marks made indentations on the stained feces.” The smell of human waste permeated the second floor of the home, they said. There were no lights in the boy’s room and the window shades were closed with duct tape so the child had no access to sunlight or even a view of the outside world … metal hooks kept the room locked from outside.

In a press conference about the arrest, Lebanon County District Attorney Pier Hess Graf said that Max Schollenberger did not live, but “existed in a state of perpetual suffering.”

At the time of his death, he weighed just 47½ pounds — or half the weight of a normal 12-year-old — and was locked inside the room 24 hours a day, 7 days a week. Graf said he was only fed table scraps when he was allowed to have food.

His siblings, who appeared to be healthy and well cared for, “were told to ignore him and not talk to him,” she added.

“Those children went to the doctor and those children went to school,” she said, noting that none of them appeared to be abused or malnourished.

“Every other room [in the house] was normal,” Graf continued. “There was an abundance of food … and that food went to every other person in the household, except for Max Schollenberger.”

Investigators say the boy died from malnutrition and head trauma. No motive has been assigned in the case.

Schollenberger and Maurer are currently being held in the county prison without bail, and their other children have been taken into care by the county Children and Youth agency.

Here’s more about the horrific case: