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 first principal was Gerald Difford. There was no senior class during the school's first year; its first graduating class was in 1975. The school colors were selected through a vote by students at Ken Caryl Junior High School and Bear Creek High School, who were the first to attend Columbine High School when it opened in 1973. The school has undergone significant renovations since it first opened: in 1995, with the addition of a new cafeteria and library; in 1999-2000 (after the massacre), with interior renovations to the corridors, cafeteria, and former library; and in the early 2000s, with the