APPLETON, WISCONSIN - The police officer who found 13-year-old Brianna Gussert dead in her bedroom described “a smell in the air of rotten food, human waste and death” inside the home, according to a criminal complaint filed Monday against the girl’s mother.

Brianna, whose disabilities left her entirely dependent on others, died primarily of sepsis after her mother left her alone in her bedroom for days on Memorial Day weekend last year, authorities said.

Her mother and caretaker, Nicole L. Gussert, 37, of Appleton didn't remember the last time she had fed Brianna or changed her diaper, Outagamie County District Attorney Melinda Tempelis said Monday as Nicole Gussert was charged in Brianna's death. She had not been bathed in more than a week.

When police were called after Brianna's death, her diaper weighed 1.25 pounds, Tempelis said.

"This poor child struggled and suffered immensely because her mom did not check on her at all," Tempelis said, calling the end of Brianna's life "a slow death."

Brianna might have been dead as long as five days before police were notified, USA TODAY NETWORK-Wisconsin learned.

Nicole L. Gussert, 37, of Appleton, who is charged with one count of child neglect resulting in death and three counts of possession with intent to deliver amphetamine.
Wm. Glasheen/USA TODAY NETWORK-Wisconsin

Greg Gussert, the father of Brianna Gussert, said the death certificate lists her estimated date of death as May 24, 2017, but her death wasn't reported until May 29. The Outagamie County Coroner's Office confirmed those dates.

Nicole Gussert was charged with one count of child neglect resulting in death and three counts of possession with intent to deliver amphetamine. The child neglect charge carries a maximum penalty of 25 years in the state prison system while each of the drug charges carries a maximum penalty of 12½ years.

She was ordered held on a $300,000 cash bond. Her preliminary hearing was set for June 19.

A police officer who responded to Nicole Gussert's home found Brianna curled up in an upstairs bedroom with her head toward the foot of her bed, according to the criminal complaint. The girl's diaper was overfilled and her appearance was "consistent with that of someone who had not been well cared for.”

The house was in disarray and had a strong smell of garbage or rotten fruit, and was filled with piles of clothes, garbage and dirty dishes. There were fruit flies in the air in the upstairs hallway.

The bag for Brianna's feeding tube was almost entirely empty when police made contact with the girl. Police found six boxes of formula on the front porch of the home.

When asked to describe the quality of care Brianna was getting in the month before her death, Nicole Gussert said “it was sub-par and she knew that,” according to the complaint.

The doctor who performed Brianna's autopsy found “there would have been noticeable change in (Brianna’s) health if she was regularly being checked on.”

Nicole Gussert told police that Brianna had not been to school “in a couple of months.” She admitted the situation could have happened partly because Nicole Gussert did not want to get Brianna ready in the morning and it was easier to call her in sick.

Greg Gussert has wondered for a year if criminal charges would ever be filed against his ex-wife.

"I feel like (Brianna's) story hasn't been told, and I don't want her life to be swept under the rug, forgotten," he told USA TODAY NETWORK-Wisconsin before Nicole Gussert was arrested Friday.

When she was born on Nov. 11, 2003, Brianna's parents were told she would probably live for 18 months, Greg Gussert said.

"She was just an inspiration and, you know, a real hero of mine," he said.

Brianna was born with Wolf-Hirschhorn syndrome, he said. The condition affects multiple parts of the body and can cause delayed growth and development, intellectual disability and seizures, according to the U.S. National Library of Medicine at the National Institutes of Health.

Throughout her life, Brianna couldn't eat on her own, speak or walk — but she was a lightning rod, her father said.

She got her point across through facial expressions and sounds. She'd wrinkle her nose when she was happy. She liked having her picture taken.

He said Brianna played baseball in the Miracle League of the Fox Valley, a league for children with cognitive and physical disabilities.

And she rooted for the Green Bay Packers and Milwaukee Brewers. It was in those teams' attire that her family asked her funeral attendees to dress in her honor.

Brianna was buried on her 14th birthday.

Greg Gussert said Brianna lived with his ex-wife, who had the space in her home to give Brianna her own room and the adjustable bed she needed. Another of their three daughters also lived in the Winnebago Street home.

At the time of Brianna's death, Greg Gussert, their third daughter and his fiancée lived in an apartment just blocks away, he said. But they had been on the verge of buying a home that would allow Brianna to live with them, too.

He has both daughters.

He said he had seen Brianna briefly in the week before he learned of her death, when Nicole Gussert dropped off one of their other daughters. Nothing seemed out of the ordinary.

"This is a tragedy," he said. "It’s a child who was taken away from her father, from her sisters, from her grandparents, from teachers and friends. She was taken too soon. She was such an inspiration and a wonderful child. And happy, she was happy all the time.

"I guess I would like people to remember her for being a child that was loved."