A truck driver has pleaded not guilty to 10 felony charges connected to a May accident involving a school bus. Forty-two-year-old Wayne Murphy is accused of driving under the influence of prescription drugs. Twenty people were injured when his semi-truck slammed into the rear of a bus carrying middle school students. Murphy said he took the medication for anxiety, but investigators think he may have taken double the prescribed dose. Murphy will return to the Columbia County Circuit Court November 6th for a status conference.