A Duluth middle-school teacher has been charged with criminal sexual conduct for allegedly having sex with a former student at her home this month.

Karla Winterfeld, 33, a teacher at Lincoln Park Middle School, was charged Wednesday in St. Louis County District Court in Duluth. Authorities say the 15-year-old boy is a former student of Winterfeld.

According to the criminal complaint, police collected evidence that included a recording of sexual acts, photographs and text messages. Winterfeld confessed to multiple sex acts with the alleged victim between May 4 and May 19, police say.

The charges do not say how police initially became aware of the relationship.

Winterfeld requested a public defender, but Judge David Johnson rejected her request, citing her current salary of nearly $73,000. He said she can reapply if she loses her job.

Winterfeld’s bail was set at $100,000. She remained in the St. Louis County jail late Wednesday.

The Duluth School District said she has been placed on administrative leave, and that the district is cooperating with police in their investigation.

Winterfeld, who has taught both health and special education classes, started at Morgan Park Middle School in 2007 and moved to Lincoln Park in 2012, according to the district. Most recently, she’s split her time between Lincoln Park and an area learning center.

According to the Duluth News Tribune, Winterfeld has received numerous accolades during her tenure, including a spot on the News Tribune’s “20 Under 40” list in 2016.