Where district court failed to account for purity of methamphetamine mixture when calculating guidelines range, court erred and error affected defendant’s substantial rights, requiring remand.The 7th U.S. Circuit Court of Appeals reversed a decision by Chief Judge Holly A. Brady, Northern District of Indiana.While executing a warrant at Jamic Johnson’s house, police officers discovered guns and baggies containing substances that appeared to be methamphetamine. Lab tests later confirmed one baggie contained 68.2 grams of a …