(USNEWS.NBCNEWS) — It was an accessory in the arsenal of Karl Pierson, the student who opened fire last week inside a Colorado high school, leaving one girl in a coma before taking his own life.

“The Anarchist Cookbook,” which Pierson read before his rampage, isn’t a guide to culinary revolution. It’s the original how-to of homicide and mass murder — and sales are still raging, with distribution from the likes of Amazon and Barnes & Noble, even as the work is linked to terrorist acts around the world.

Now, in rare interviews with NBC News, the publisher and the author of the “Cookbook” are trading blows about the book’s future.
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“’The Anarchist Cookbook’ should go quietly and immediately out of print,” says William Powell, who wrote the book as a stern 19-year-old, an opponent of the Vietnam War who felt violence was justified if it could prevent even greater violence in the process. He has since renounced that position, but never so forcefully, telling NBC in an email that “it is no longer responsible or defensible to keep it in print.”

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