ELKO, Nev. (AP) — A 61-year-old Elko County woman accused of killing her adult daughter with autism has pleaded not guilty to one count of open murder.

The Elko Daily Free Press reports Judith Zavala entered the plea Monday during her arraignment for the strangulation death of 24-year-old April Zavala.

Court documents indicate the mother told police she didn't call 911 because she "panicked" after she "snapped" during a struggle as she tried to get her daughter out of bed and dress her on June 14.

She told police her daughter was autistic from the age of 3 but in recent months was subject to more violent outbursts.