Columbine High School massacre Potential Students") program. He found the transition to Ken Caryl Middle School difficult. Unlike the white caps of the jocks, Harris and Klebold wore black baseball caps. As was typical in the 1990s, they wore them backwards. Harris wore a KMFDM cap, and apparently did not wear it during the massacre. Klebold's cap had a Colorado Avalanche logo on the front and a Boston Red Sox logo sewn onto the back. Following the Columbine shooting, schools across the United States instituted new security measures such as see-through backpacks, metal detectors, school uniforms, and security guards. Some schools implemented school door
Columbine High School massacre flying glass and hitting Nielson in the shoulder with shrapnel. Anderson and Nielson ran back down the hall into the library, and Nielson alerted the students inside to the danger, telling them to get under desks and keep silent. She dialed 9-1-1 and hid under the library's administrative counter. Anderson fell to the floor bleeding from his injuries, and hid inside an open staff break room. Harris removed his trench coat. At 11:22 a.m., the custodian called Deputy Neil Gardner, the assigned resource officer to Columbine, on the school radio, requesting assistance in the senior parking lot. The only paved