Jose Luis Flores Aca pleaded guilty Friday to first-degree intentional homicide and first-degree sexual assault. A charge of hiding a corpse was dismissed.
The body of 36-year-old Jamie Koch was discovered in her burned vehicle on Aug. 7, 2013.
According to the criminal complaint, Flores Aca told detectives he was angered when Koch grabbed his arm, so he punched her, strangled her and sexually assaulted her corpse. Flores Aca told detectives he then drove her body to Waupaca County, parked in a field and set the car on fire.
His trial was scheduled to begin next month. WSAW-TV reports sentencing is set for Sept. 30.