Authorities do not know how Spengler obtained the Bushmaster rifle, .38-caliber revolver and 12-gauge shotgun he used, Pickering said.

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He was also armed with a 38-caliber revolver and a 12-gauge shotgun, they said.

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There is no drug that is going to shed trustworthy light on Holmes' state of mind last year when, police say, he donned a gas mask as well as full body armor and grabbed a rifle, a pump-action 12-gauge shotgun and at least one .40-caliber semiautomatic pistol to launch a heinous attack.

CNN: 'Truth serum' won't reveal mind of James Holmes