WINONA, Minn. – Police traced an online chatterbox threat to “shoot up” the Winona Middle School and then on to the high school to a 13-year-old girl. The girl was confronted at home about 11 a.m. and confessed, police said. Why did she do it? She told officers that she djdn’t want to go to school that day. No firearms were located. In conclusion, police said, the threats were not credible. The child was left in the care of a guardian. The threats were through the online platform Snapchat and spread contagiously among fellow students. Police said they traced the source of the messages through interviews and deduction. Meanwhile, investigators began drafting a recommendation to the county prosecutor for felony charges of terroristic threats.