Video - National News
Posted on April 9, 2014 at 7:34 AM
Updated Wednesday, Apr 9 at 7:20 PM
Flailing away with two kitchen knives, a 16-year-old boy with a “blank expression”stabbed and slashed 21 students and a security guard in the crowded halls of his suburban Pittsburgh high school Wednesday before an assistant principal tackled him.
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Credit: AFP/Getty Images