A former Lehighton man has been indicted on charges that he wrote a prison letter in which he threatened to kill President Barack Obama.

Gregory Dale Brockman, currently housed at the state prison in Chester, also allegedly threated to eat the flesh of Obama, sexually assault first lady Michelle Obama, and then "skin her alive," according to court papers.Brockman allegedly made the threats against Obama in a letter he handed to a psychologist in the Chester prison. He allegedly described how he would kill Obama. He even detailed his cannibalized intentions regarding Obama.Brockman, 32, is accused of making the threat after having been removed from his cell for threatening to kill his cell mate.He entered a plea of not guilty during his appearance yesterday in U.S. District Court, Philadelphia, before Magistrate Judge David R. Strawbridge. If convicted, he could face 51 to 63 months in a federal prison.In the indictment which was dated Nov. 18, Brockman was charged with "threat against president," "threat against immediate family member of president," and "threat against former president."It's the second time he has been in trouble with the law for threatening the president of the United States.In 2007, he threatened to kill then president George W. Bush. In 2008, U.S. District Judge James M. Munley, presiding in the U.S. District Court in Scranton, accepted a guilty plea and ordered Brockman to serve a 30-month sentence, which ran concurrently to unrelated criminal charges for which he was serving time in Carbon County, and to serve three years probation.Judge Munley did not impose a fine, stating that Brockman "does not have the ability to pay fine."Brockman has a long criminal record, which includes criminal arrests in Carbon and Berks Counties, according to court records.