In January, career criminal Gregory Dale Brockman handed a letter to a psychologist at the state prison in Chester after he had been removed from his cell for threatening to kill his cell mate, federal prosecutors said Thursday in a court filing.

Authorities there contacted the U.S. Secret Service after they saw the letter.

Brockman, 32, formerly of Lehighton, Carbon County, said in the letter that he planned to kill President Obama, sexually assault First Lady Michelle Obama, then "skin her alive," according to court papers.

He also described how he would kill Obama. Afterward, he planned to "cut [Obama's] meat from his bones and put them in the oven," then "sit down at the table and start eating," the court filing said.

Brockman allegedly told federal agents during an interview in February he was fascinated by serial killers and especially identified with Jeffrey Dahmer. (Dahmer murdered 17 men and boys between 1978 and 1991, and cannibalized some of his victims.)

A tall, balding man with glasses and a beard, Brockman was serving a 3-to-10 year sentence in state prison for a 2007 burglary conviction when he was indicted last month for threatening to kill the President, the First Lady and former President George W. Bush.

He appeared before U.S. Magistrate David Strawbridge Thursday, pleaded not guilty to the charges and was ordered held for trial. If convicted of all charges, Brockman could face 51 to 63 months in a federal lockup.

Brockman has a 2008 conviction for threatening Bush.

In July 2008, he pleaded guilty in federal court in Scranton to threatening Bush and was sentenced to 30 months in a federal pen in Oct. 2008.

Court papers said Brockman was interviewed by two Secret Service agents on Feb. 2 at the state prison in Chester.

During the interview, he admitted writing the letter found in his cell and a letter he wrote and mailed to the Secret Service's regional office in Scranton, which was postmarked on Jan. 19, 2010.

Court papers said Brockman wrote the letters because he was "agitated" with Obama after reading a newspaper article about the deaths of nine Americans in Iraq. The article also reportedly said Obama intended to send additional troops to Afghanistan.

Brockman was allegedly distressed that the U.S. was spending money abroad and not helping Americans at home. He thought about killing Obama and his family and jotted the thoughts down on paper to calm himself, prosecutors said.

He later decided to send a letter to the Secret Service in Scranton.

Court papers said Brockman also told agents he really wanted to harm the president and wanted the government to legalize marijuana and spend money on education and domestic programs.

Brockman allegedly told agents that if he was released from prison he would act on his thoughts.