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 Three days before the shooting, Klebold attended the high school prom with Anderson. Both Harris and Klebold held part-time jobs at a local Blackjack Pizza. Through Philip Duran, a coworker, Klebold bought a TEC-9 handgun from Mark Manes for $500 at another gun show on January 23. After the massacre, Manes and Duran were both prosecuted. Each was charged with supplying a handgun to a minor and possession of a sawed-off shotgun. Manes and Duran were sentenced to a total of six years and four-and-a-half years in prison, respectively. In addition to the shootings, the complex and highly planned attack