OSHKOSH (WLUK) -- A teen accused of stabbing a school resource police officer at Oshkosh West High School has withdrawn his "insanity" plea, and will go to trial.

Grant Fuhrman, 18, is charged with one count of attempted first-degree intentional homicide for the Dec. 3, 2019 incident. Prosecutors say Officer Mike Wissink shot Fuhrman after Fuhrman stabbed him. Students and staff evacuated, and classes were cancelled for two days.

Wissink recovered. He retired in March.

Online court records indicate Fuhrman changed his plea on Friday.

A 14-day trial is set for December.