A teen who fatally shot another student at his suburban Denver high school last year had been deemed “not a high-level of threat” after shouting a death threat against his debate coach three months earlier, reports the Associated Press. Karl Pierson, 18, was allowed to return to class less than a week after he was demoted from captain of the debate team and said he would kill the coach, who was a school librarian. Documents obtained by the AP show once again the difficulty of accurately assessing threats by potentially dangerous students.
Pierson entered Arapahoe High School on Dec. 13 with a shotgun, a machete and homemade bombs. He killed a 17-year-old girl before taking his own life. School districts across the country have bolstered physical safety since tragedies such as the 1999 shooting at Columbine High School in Colorado, but they have focused less on preventative efforts such as how to thoroughly assess a threat. Said one expert, “When you’re dealing with human behavior, it’s not a simple check-the-box, yes-or-no, black-or-white answer. It’s gray.”