But according to the affidavit, Dutschke insisted that he'd never researched anything about ricin and that he'd never even seen a castor bean.

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Dutschke, the affidavit stated, also said he'd never researched anything about ricin, a toxin derived from castor beans that has no known antidote.

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But investigators said that a search of his computer -- dating to an arrest on unrelated charges early this year -- showed that he'd downloaded a publication, "Standard Operating Procedure for Ricin" about safely handling the toxin and another file, about two hours later, about a method for detecting ricin.

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