A martial arts expert pleaded guilty of helping al-Qaida by teaching fighting skills.
The deal means Tarik Shah, who also is a jazz musician, faces 15 years in prison instead of the 30 years he could have faced if convicted at trial.
Shah, 44, pleaded guilty Wednesday to conspiring from October 2003 through May 2005 to provide martial arts and hand-to-hand combat with weapons training, knowing that al-Qaida was engaged in terrorism.
"I agreed with others to provide material support to al-Qaida in the form of martial arts training, which I knew was wrong," he told U.S. Magistrate Judge Gabriel W. Gorenstein.
A prosecutor asked Shah to say he knew that al-Qaida was a terrorist group, but Shah, after a pause of several minutes to consult with his lawyer, agreed only that he knew the United States had classified al-Qaida as a terrorist organization.
Prosecutors alleged Shah met May 20, 2005, with an undercover FBI agent he thought was an al-Qaida recruiter. During the meeting, he pledged allegiance to Osama bin Laden and al-Qaida and agreed to provide martial arts expertise to al-Qaida fighters, according to court documents.
Prosecutors also said Shah met multiple times with a confidential source and an FBI undercover agent, expressing a desire and intention to help al-Qaida by recruiting others.
Among materials recovered from Shah were names and telephone numbers of other people, including Seifullah Chapman, a member of what the government called a "Virginia jihad network" that prepared to join the Taliban by playing paintball near Fredericksburg, Virginia, in 2000 and 2001. Chapman was convicted in Virginia in 2004 and sentenced to 65 years in prison.
Shah's sentencing was set for July 10.
On Monday, Shah's co-defendant Mahmud Faruq Brent Al Mutazzim, of Gwynn Oak, Maryland, a Washington, D.C., cab driver, pleaded guilty to providing material support to the Lashkar-e-Taiba organization, which the U.S. designated a terrorist organization in 2001.
Another co-defendant, New York bookstore owner Abdulrahman Farhane, pleaded guilty in November and is to be sentenced next week.
Dr. Rafiq Abdus Sabir of Boca Raton, Florida, is the only defendant who has not pleaded guilty. He is to go to trial April 24 on charges of agreeing to treat holy warriors in Saudi Arabia.
Sabir has argued through his lawyers that it was unconstitutional to prosecute a doctor for providing medical services.