A former Prescott substitute teacher was fired. Now, she faces felony charges for having sex with a 13-year old student.

A Pierce County judge ruled the case will go to trial.

Thirty-nine-year-old Anne Knopf is charged with felony sexual assault of a child under the age of 16.

Anne Knopf isn't in jail. The judge released her on a $25,000 signature bond. Monday, she was fingerprinted and jailers took her mug shot at the Pierce County Sheriff's Department. The judge says she cannot have any contact with the boy or his family.

"We take these cases very seriously, the potential penalty is very serious," said Pierce County District Attorney John O'Boyle. "But this case is still in its infant stages, with the preliminary hearing down the road. There's nothing to prove guilt yet."

"It's really not the time to make any comments about the allegations," said Knopf's defense attorney Fred Bruno.

Knopf is accused of having sex with a 13-year-old male student, between January 1 and May 18 of this year.

The criminal complaint states the boy drove his mother's vehicle to Knopf's rural Ellsworth home, once a week, for about four or five weeks.

Court records show this happened between 11:00 p.m. and 1:00 a.m., when the two would kiss and have sex.

The complaint also states the two would e-mail and instant message each other.

For the past two years, Knopf worked as a substitute teacher in the Prescott School District, including at the middle school, where the boy is a student.

"Nothing indicates anything happened at school but having found out the allegations, we take them very seriously," said Prescott School District Superintendent Roger Hulne. "She's a substitute teacher and we suspended her immediately from the school district."

Hulne says that suspension later turned into a termination: he says Knopf no longer works for the district.

Knopf will be in court again November 20.

Her defense attorney says she will plead "not guilty" then.

If convicted, Knopf could face up to 40 years in prison.