GREENVILLE, South Carolina, March 2 -- The office of the U.S. Attorney for the District of South Carolina issued the following news release: Alvin Bernard Parks, 42, has pleaded guilty to sending a threatening letter to a federal judge through the mail. According to court documents, Parks is alleged to have sent a letter to a specifically named United States District Court Judge for the District of South Carolina. The handwritten letter contained threats to harm the judge. An excerpt from the   more