Albany police searched the school twice -- the first time on the night they arrested Acord.

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Acord with manufacturing a destructive device with the intent of detonating it at a school.

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Acord, a juvenile, will be charged "as an adult with attempted aggravated murder, " Haroldson said.

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The 1999 shooting spree at Colorado's Columbine High School served as Grant Acord's benchmark and inspiration, Benton County District Attorney John Haroldson said.

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With the help of explosive devices, checklists and diagrams, Acord's "goal was to model the Columbine shootings with some adjustments that would make it a greater success, " Haroldson said.

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