A former assistant attorney general could go on trial on child pornography charges as soon as next month. Tuesday, a federal judge ruled to dismiss three motions in the case, that claimed politics lead to the charges against 46-year-old James Cameron. Cameron pleaded not guilty in February to 16 counts of transporting, receiving and possessing child pornography.Cameron’s lawyer claimed his client was being prosecuted because of political differences between the Maine Attorney General’s Office and the U.S. Attorney’s Office.The judge rejected that and set jury selection for next month. Cameron was the state’s top drug prosecutor until he was fired in April of last year. An investigation revealed that between july 20-06 and january 20-08, Cameron allegedly uploaded child pornography to a Yahoo photo album under multiple screen names.The investigation also showed he was sending digital images on-line.