He said the shooter was a 17-year-old from Coleman and was dead on the scene. He was not a student at the school.
The girl, whose name was not released, is a student at H.H. Dow High School, but was not in class Wednesday morning. She is from Midland.
St. Louis said the gunman called her at home and asked her to meet him at the school. After a conversation in the parking lot, he pulled a gun out of a backpack and shot her four times before turning the gun on himself.