On December 7, 2017, Aztec High School in Aztec, New Mexico, was the scene of a school shooting that killed two students, including 17-year-old senior and cheerleader Casey Jordan Marquez. The shooter, 21-year-old former student William Edward Bill Atchison, entered the school disguised as a student, hid in a second-floor bathroom, and opened fire; witnesses and reports say Marquez and a 17-year-old junior, Francisco Fernandez, were both shot multiple times in the halls and died at the scene.

Atchison reportedly had a long history of troubling behavior: he had been bullied, was once stabbed during a welding class, was suspended in 2012 after writing the Columbine schedule on a whiteboard and disenrolled, and drew FBI attention in March 2016 after online posts about committing a mass shooting. The FBI’s inquiry did not result in further action toward the school or in securing a weapon. Atchison moved through the school firing into classrooms before killing himself at 8:16 a.m.

Teachers’ quick barricading of classrooms is credited with limiting casualties. No arrests were made; the perpetrator died at the scene. If anyone knew Casey or has information about her final day, please share what you know.