A dad and a stepmom are facing murder charges in the death of an 8-year-old girl in Elk River, Minnesota, last week.

Brett Hallow, 30, and Sarah Hallow, 28, are both charged with second-degree murder and first-degree manslaughter in the death of Autumn Hallow.

According to the charges, at 3:45 p.m. Thursday, police responded to an apartment on 172nd Avenue in Elk River on a report that a juvenile was found partially submerged in the bathtub. When they arrived, they found Sarah attempting chest compressions on a young girl, later identified as Autumn, in one of the bedrooms.

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Police tried to revive Autumn Hallow, but she was declared dead at her family's home.

Officers attempted to revive Autumn, but she was declared dead at the scene.

Based on the condition of her body, officers believed Autumn had been dead for some time. They observed she was “extremely frail and thin” and had lacerations and pin-like marks on her forehead, as well as partial hair loss and bruising, the charges say.

Sarah told officers Autumn told her she was going to take a shower. She said she went to check on Autumn 40 minutes later and found her face down in inches of water in the bathtub. She and Brett moved Autumn to the bedroom and called 911.

Officers noticed there was no water in the bathtub, but there were feces in the back of the tub. The floor of the bathtub appeared to have been cleaned recently. Crime scene technicians with the Minnesota Bureau of Criminal Apprehension determined there had been blood in various spots in the bathroom, mostly in the shower.

Brett and Sarah Hallow were charged with murdering the 8-year-old girl. (Sherburne County Jail)

The Midwest Medical Examiner ruled Autumn’s death a homicide and determined she died of asphyxial injuries and blunt force trauma.

“The medical examiner described Victim’s thin appearance as ‘markedly cachectic’ with scant fatty tissue, atrophic musculature, atrophic thyroid and marked hair loss,” the charges say.

There were three other children who lived at the home, ages 3, 6 and 10.

Investigators and child protection workers interviewed the Hallows’ 6-year-old son and Sarah's 10-year-old daughter, who both told them the Hallows would tie up Autumn with a brown braided belt, a black hooded sweatshirt or a long, gray shirt if she was in trouble, often placing her in a red sleeping bag.

The son said Autumn would sometimes sleep in the sleeping bag overnight in the living room, kitchen and, on one occasion, in the bathtub.

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The son said when Autumn was tied up in the sleeping bag, she would only be allowed to eat or drink when Sarah, Brett or the other daughter would bring it to her.

The morning of Autumn’s death, the son said he heard her screaming in the bathroom and he heard Sarah telling her to clean up the mess in there. He said Brett went into the bathroom and he heard a loud bang. The son said Sarah told him Autumn had fallen down.

The daughter also said she saw both Sarah and Brett go into the bathroom and that Sarah told her there was blood in the tub and Autumn was not breathing.

When searching the apartment, law enforcement found the items the children described the Hallows using to tie Autumn up as well as the red sleeping bag. The black hooded sweatshirt and gray shirt were located in a towel and covered in vomit.

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Several bottles of cleaning supplies were located in the kitchen. Officers also found shopping bags containing garbage in the master bedroom, including human hair and a paper towel with a red substance.

Both Sarah and Brett denied restraining Autumn or putting her in the sleeping bag for discipline. Sarah said she had noticed Autumn was losing weight as well as her hair, but did not take her to the doctor.

This story first appeared on Fox 9.