Zachary Chesser in court, July 22 (Sketches by: Bill Hennessy Jr.)

A Virginia man admitted in federal court Wednesday that he recently tried to join an Al Qaeda-linked group in East Africa and, months earlier, threatened the creators of the television show “South Park.” But 20-year-old Zachary Chesser has now “totally renounced violent jihad,” according to his defense attorney.

Chesser was arrested in July at John F. Kennedy International Airport in New York, as he was attempting to leave for Somalia with his infant son and join Al Shabab, which has been fighting to establish a strict Muslim state in Somalia and was designated a foreign terrorist organization by the U.S. government in early 2008.

In an Alexandria, Va., court Wednesday, a clean-shaven Chesser pleaded guilty to providing material support to a terrorist group, communicating threats and soliciting others to threaten violence. He told U.S. District Judge Liam O’Grady that between late 2009 and mid-2010 he posted videos and messages online that advocated “jihad” and encouraged Muslims to attack Americans and U.S. interests overseas.

“Zachary Chesser seriously endangered the lives of innocent people who will remain at risk for many years to come,” Neil MacBride, the U.S. Attorney for the Eastern District of Virginia, said in a statement. “His solicitation of extremists to murder U.S. citizens also caused people throughout the country to fear speaking out – even in jest – lest they be labeled as enemies who deserved to be killed.”

After an episode of “South Park” depicted the Prophet Muhammad in a bear suit, Chesser posted a message online in April saying, “We have to warn [the creators] that what they are doing is stupid and they will probably wind up [dead].” Chesser then posted a lecture by U.S.-born cleric Anwar Awlaki, calling for the assassination of anyone who has defamed Muhammad. Readers should “pay them a visit,” Chesser said.

Similarly, after a Facebook user organized “Everybody Drawy Muhammad Day,” Chesser compiled photos, names, addresses and other personal information of people who supported the idea. He gave that information to associates “inclined to engage in violent jihad” and who “were capable” of harming others, O’Grady said.

In other posts, Chesser urged readers to conduct “fake” operations by leaving suspicious packages in public places, thereby “desensitizing” law enforcement officials to what one day would be a real bomb. “Boom! No more [non-believers],” Chesser wrote.

MacBride said today’s guilty plea is a reminder “of the serious threat homegrown jihadists pose to this country.” But Michael Nachmanoff, Chesser’s publicly-appointed attorney, said Chesser’s case is “different” from other recent terrorism cases.

After Faisal Shahzad, the failed Times Square bomber, was recently sentenced to life in prison, he expressed pride in what he had done. Chesser, by contrast, is “deeply remorseful,” Nachmanoff said.

Nachmanoff described Chesser as “a young man who has taken some very important steps toward putting his life back to together,” starting with the guilty plea on Wednesday.

During Wednesday’s 40-minute court hearing, Chesser’s mother, father and a small group of other supporters sat behind him in the courtroom. Chesser’s wife, Proscovia Kampire Nzabanita, was not present.

Two days earlier, federal prosecutors charged Nzabanita with providing false statements to investigators during their months-long investigation into her husband.

In June, Chesser “instructed his wife falsely to deny knowledge of his planned trip to Somalia to join Al Shabab if she was questioned about him by law enforcement authorities, and instead assert that he went to Uganda to pick up her birth certificate,” according to court documents.

As part of Chesser’s plea agreement with federal prosecutors, his wife will not face charges for what judge O’Grady described as “aiding and abetting” Chesser’s illegal activities. A native of Uganda, she is instead expected to be deported from the United States.

As for Chesser, he faces up to 30 years in prison. As part of the plea agreement, prosecutors will not recommend he be placed in a “supermax” facility, and Chesser’s defense team will not request a sentence of less than 20 years’ imprisonment.

A sentencing hearing is scheduled for late February 2011.