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 friend Dylan Klebold and others. The mascot of Columbine High School (CHS) is the Rebels, and he called these "Rebel Missions". Harris and Klebold adopted the nicknames "Reb" and "Vodka" respectively. Beginning in early 1997, the blog postings began to show the first signs of Harris's ever-growing anger against society. By the end of the year, the site contained instructions on how to make explosives. Harris wrote "the first true pipe bombs created entirely from scratch by the rebels (REB and VoDkA)...Now our only problem is to find the place that will be 'ground zero.'" Harris's site attracted few visitors,