Investigators on Tuesday are focused on trying to determine a motive in a Wisconsin school shooting that left a teacher and a student dead and two other children in critical condition. Shon Barnes, the police chief in Madison said investigators were aware of a “manifesto, if you want to call it that, or some type of letter” posted by someone who might have known the shooter, 15-year-old student Natalie Rupnow. “We haven’t been able to locate that person yet, but that’s something we’re going to work on today,” Barnes told CNN. “We’ll also be looking through (Rupnow’s) effects, if she had a computer or cell phone, to see if there are any transmissions between her and someone else, and that will give us an idea of what type planning.” Police responding to the shooting Monday at Abundant Life Christian School found Rupnow had a self-inflicted gunshot wound. The shooter died on the way to a hospital. Police said the shooting occurred in a study hall. Besides the deaths, six people were wounded, including two students who remain in critical condition. MORE: https://www.wthr.com/article/news/nation-world/wisconsin-school-shooting-suspect-identified-victim-details/507-6a121663-bb9b-4486-94ed-f24a9392e884