On December 17, 2015, Brooke Higgins and her accomplice, Sienna Johnson, walked into Mountain Vista High School and opened fire on school faculty and other students before taking their own lives.

That’s how this story would have begun if everything had gone to plan. Thankfully, the two girls who had fantasized for months about their plans to pull off a Columbine-style shooting were thwarted by an anonymous tip days before that plan was originally set to be executed.


In a purple spiral-bound notebook Higgins documented the months and weeks leading up to her arrest. Higgins admitted that she had been regularly using cocaine and wrote that she couldn’t figure out why she feels much sadder than everyone else around her. She also writes about her frustrations with her family, her thoughts of suicide, and expresses love and understanding for her two idols – Eric Harris and Dylan Klebold, who in 1999 shot and killed 12 students and a teacher at Columbine High School before shooting themselves. This notebook was among the evidence collected from the bedroom of then 16-year-old Brooke Higgins on December 12, 2015.

Then 16-year-old Sienna Johnson also kept journals about her plans to attack the school and her unhappiness. Some of these entries she posted publically on a website she maintained.


Though the girls had been planning the attack for several months prior to their arrests, the girls’ scheme had slowly begun to fall apart. Originally, Higgins and Johnson agreed that December 17, 2015, would be the best day to attack the school because it would be right before Christmas break and have the most impact. As that date rapidly approached, the girls realized that they still had not obtained any weapons, nor had they had the opportunity to practice. Together, the girls decided that it would be better if they waited until after the new year, postponing the attack until sometime between January and April of 2016.


Both girls were charged with conspiracy to commit murder. Initially, Higgins and Johnson were charged as both adults and juveniles, so certain records could be unsealed as their trials progressed and so that the judge presiding over their cases could later rule what sort of sentencing would best serve the community at large and the defendants. These charges were later turned over to the juvenile courts.

Higgins has since pleaded guilty to the charges and has made an apology to the community. She has been sentenced to three years in the Department of Youth Corrections. Johnson’s case is still underway and is still under the presumption of innocence until proven otherwise.