A MUSLIM convert from New York who ran a website that posted threats against the creators of the television show South Park is expected to enter a federal guilty plea, his lawyer said.

Jesse Curtis Morton, also known as Younus Abdullah Mohammad, was charged last year with communicating threats and has been in custody since he was arrested in Morocco in October.

A plea agreement hearing in the US District Court in Alexandria has been scheduled for today.

Morton's lawyer, James Hundley, confirmed he will plead to three counts, including conspiracy and communicating threats.

Each count will carry a maximum sentence of five years, Mr Hundley said.

Last year, another operator of the Revolution Muslim website, Zachary Chesser, was sentenced to 25 years in prison. He admitted he posted threats against the South Park creators for an episode that supposedly defamed the prophet Muhammad.

Chesser went even further, twice trying to travel to Somalia to join the terrorist group al-Shabab. On his second attempt, he travelled with his infant child in tow on the theory that he would appear less suspicious to authorities.

Chesser's lawyer portrayed his client as a drifting teenager who latched on to activities and philosophies with a freakish intensity. Before converting to Islam, he participated in high school sports and later joined a Korean breakdancing team at his school.

He spent years as a vegetarian and dabbled in Buddhism. He became so fascinated with Japanese anime that he spent four years studying Japanese and travelled to Japan on a school trip.

And, when he became infatuated during his senior year with a Muslim girl, he converted to Islam. He quickly drifted toward a radical, fundamentalist interpretation of the religion.

An FBI affidavit states that Chesser and Morton met in person only once and coordinated closely in trying to craft statements that would threaten and terrorise the South Park creators, Trey Parker and Matt Stone, but could also be plausibly protected under constitutional guarantees of free speech.

Specifically, the two crafted a statement that said "it is likely the creators of South Park will indeed end up like Theo Van Gogh", a Dutch filmmaker who was murdered in 2004 for making a movie that was perceived as insulting to Islam.

Hundley said free speech issues were certainly a part of the case, but that his client ultimately made the decision to plead guilty.

"It's a speech case," he said. "Is this free speech or speech that crosses the line into criminal conduct?"

Originally published as Man in court over South Park threat