A northeast Texas man has pled guilty to federal drug charges. 42-year-old Keith Earl Kates of Deberry -- in Panola County -- has admitted to possessing pseudoephedrine with the intent of manufacturing methamphetamine. Court records show that Kates purchased cold pills containing pseudoephedrine at Walgreens and Walmart stores in Marshall back in May of 2010. A year later, he was indicted on the charges by a federal grand jury. When he's sentenced, he could be facing up to twenty years in federal prison.