A Pennsylvania woman has been arrested and charged with child endangerment after her 4-year-old son, who had autism, was found dead in their home, authorities said.

Amie Ruleman, 40, was taken into custody on April 8 in Waynesboro, according to the Waynesboro Police Department.

According to charging documents cited by local outlets including Local 12, WGAL, and FOX 43, Ruleman contacted police on Tuesday, reporting that her son was unconscious and not breathing inside their home.

Investigators allege that Ruleman told officers she had first noticed the child in an unusual position earlier that morning. She reportedly said she briefly woke up around 4 a.m. and saw her son kneeling in the same spot. When she woke again around 11:30 a.m., the child was still in that position and had not moved.

Police said Ruleman told them the child had remained motionless for approximately nine hours.

According to the charging documents, Ruleman took a photograph of her son while he was in that position and sent it to a family member before attempting to wake him. Around 12:35 p.m., she tried to rouse the child and discovered his body was cold. She then called police.

Emergency responders arrived at the home, but the child was pronounced dead at the scene.

The coroner later determined that the child had been dead for approximately 24 hours by the time authorities arrived, according to WGAL.

Ruleman has been charged with endangering the welfare of a child. Court records do not yet indicate whether she has entered a plea or retained legal representation.

Authorities have not released additional details about the cause of death, and the investigation remains ongoing.