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Father's fight for change persists 25 years after Columbine
6m 9s
It’s been 25 years since 12 students and one teacher were killed in the Columbine massacre in Littleton, Colorado. It was the largest mass killing at a high school in U.S. history at the time. But since then, school shootings have grown to higher levels. Amna Nawaz discussed more with Tom Mauser, whose son, Daniel, was killed at Columbine that day.