Court documents filed in Natrona County Circuit Court last week detail brutal abuse a Mills couple allegedly inflicted on a 12-year-old that led a doctor to say "right now, if we don't do anything, he will die very quickly."

Charging documents filed against Ryan Lewis Hilyard and Sarah Marie Hilyard allege they caused injuries to a 12-year-old that left the child needing to be intubated and required him to have part of his skull removed.

Ryan Lewis Hilyard is charged with attempted second-degree murder, aggravated child abuse and child abuse. If convicted on each charge, he could face decades behind bars.

Sarah Marie Hilyard is charged with attempted second-degree murder, aggravated child abuse and two counts of child abuse.

Mugshots for Ryan and Sarah Hilyard were not immediately available. All of the children in their household were taken into protective custody when the investigation began, according to the affidavit.

According to an affidavit of probable cause filed last week, Mills police began a lengthy investigation after they were called to Wyoming Medical Center on August 6 following a report of child abuse.

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The affidavit alleges that Sarah Hilyard brought the 12-year-old boy — who was identified in court documents as her stepson — to the hospital after calling staff and reporting that he was unresponsive.

When the child was brought in, he had to be intubated and scans showed brain bleeding and swelling, which had shifted his brain more than a centimeter offline.

Additionally, medical staff noted that the child was suffering from respiratory failure and a retinal hemorrhage.

The child was also suffering from a severe traumatic brain injury.

According to the affidavit, Sarah Hilyard told investigators that the child fell down the stairs a day or two before the hospital visit but she did not know what caused the injuries. She also explained to investigators that the child was "a little more tired than usual" but chalked it up to puberty.

The affidavit alleges that the child had gotten into fights with his brother and step-brother who are 9- and 10-years-old, respectively.

Court documents state that Ryan Hilyard too told police that the 12-year-old fell down the stairs. Hilyard also allegedly told police that he didn't see what happened but was just taking his "best guess."

When police conducted a search warrant at the Hilyard's residence, they discovered that someone had recently attempted to clean up vomit from the child's room. Officers also reportedly found soiled clothing.

Police also allegedly found door alarms in the child's room and bathroom directly across from his room that "were in working order and obnoxiously loud."

"The kitchen had locks on the cupboards with food," a detective writes in the affidavit. "The fridge/freezer combo had locks on the fridge and freezer."

The affidavit states that Sarah Hilyard told investigators in a subsequent interview that the child fell down the stairs and hit his head on the bottom. Later in the interview, Sarah Hilyard reportedly told police the child was "running stairs for punishment" when he fell and hit his head. Eventually, she told investigators she was running stairs and may have thrown her arm at him in frustration and he fell backward.

According to the affidavit, police found bruise cream in the child's room. Sarah Hilyard explained that she knew how the bruises looked on the child and how it would reflect on her and Ryan Hilyard.

She also reportedly told police that it took her four days to take the child to the hospital because she thought he was getting better. The affidavit states Sarah Hilyard told investigators that she knew the child was unable to speak. She also had to help him to the bathroom because he could not walk.

"It's been hell with him" she allegedly said during the interview.

Police also noted Sarah Hilyard had nothing nice to say about the child, court documents state.

But a child who witnessed the incident painted a far more brutal picture.

One of the siblings in the case told police that Ryan Hilyard told them people were going to come over and ask them questions and to simply say the victim fell down a flight of stairs, according to court documents. The sibling added that they were afraid to tell the truth because Ryan Hilyard picks them up by their throats on numerous occasions. In one case, the child said Ryan Hilyard pushed his head into a stuffed animal for two minutes, making it hard to breathe.

According to the affidavit, the step-sibling eventually told police that Ryan Hilyard was making the 12-year-old run up and down the stairs and was punching him. Ryan Hilyard was also punching the victim and dragging him up and down the stairs before pushing the victim down the stairs.

When Ryan Hilyard allegedly pushed the child down the stairs, his sibling described it as seeming as though he had no bones, according to the affidavit.

At some point, it appeared as though the victim had fainted.

At another point, Ryan and Sarah Hilyard told the victim's 10-year-old step-sibling that he needed to push him down the stairs.

Another sibling described the 12-year-old as being "So beat up, he was crawling and then, so then they pushed him," the affidavit states. "His head hit the edge of the bottom stairs, and he stood up and fell back down."

After the victim fell down the stairs and was knocked out, Ryan and Sarah Hilyard reportedly yelled, punched and kicked him while he was on the ground while saying "stop faking it, get up," according to court documents.

Then they took him to his room and his step sibling never saw him after that.

Another sibling told investigators that, after the 12-year-old was knocked out, Ryan and Sarah Hilyard left him in a closet in his room and explained that's where he lived now.

During the investigation, children from the Hilyard household were reported to be constantly hungry and digging in the trash for food while at school, the affidavit states.

School staff also reported that the Hilyards told the children not to see the school nurse or school counselor, court documents state.

The victim's siblings also described instances where Ryan and Sarah Hilyard would find any excuse to get them in trouble, according to the affidavit. One frequent "punishment" carried out by Sarah Hilyard involved a child being put into a bathtub and having ice-cold water poured on them.

Police were granted a search warrant for Sarah Hilyard's phone. On her phone, they found a video in which investigators could hear Sarah Hilyard taunting the victim. He describes wanting food and water really badly, to which Sarah Hilyard says he's already had some.

At that point, Sarah Hilyard continues to taunt the child, describing his "f---ed up little brain," the affidavit states.

According to the affidavit, a detective told Sarah Hilyard that it was almost like she hated the child.

"If I hated him like you said, I would have just let him die," she allegedly replied. "But I didn't."