Police are investigating the online footprint of the 15-year-old girl who allegedly opened fire at her Madison, Wisconsin, Christian school.

A 15-year-old female student killed a teacher and a student at the private Abundant Life Christian School in Madison, Wisconsin, on Monday.

I just heard shotting [sic],” 8-year-old Nora Gottschalk said. “And then there was a teacher and she was screaming like, ‘Ahh, my leg! Help! Help!’”