Former ‘enemy combatant’ pleads guilty in Ill.

updated 8:23 p.m. ET April 30, 2009

PEORIA, Ill. - An al-Qaida sleeper agent who was locked up without being charged for years pleaded guilty Thursday to supporting terrorism in the months before and immediately after the Sept. 11 attacks.

Ali al-Marri, 43, a married father of five who was attending college in this central Illinois city when he was arrested, admitted to one count of conspiring to provide material support or resources to a foreign terrorist organization.

He faces up to 15 years in prison at his July 30 sentencing.

"We thought (the plea) was the right approach to take based on the evidence the government allowed us to review over the last several weeks," said al-Marri's attorney, Andy Savage.

Plea negotiations have been going on since before al-Marri's initial court appearance in March, Savage said.

"It was not an easy negotiation," he said.

Al-Marri, a legal U.S. resident and native of Qatar, was arrested in late 2001 while studying at Bradley University after federal authorities alleged he was tied to organizers of the 2001 attacks.

The Bush administration declared al-Marri an "enemy combatant" in late 2001 and held him without charges for more than five years at a Navy brig in South Carolina. The designation was dropped when he was indicted by a federal grand jury in Illinois.

Al-Marri got a bachelor's degree in business management administration from Bradley in 1991, then went to work for a bank in Qatar. The government said he met with Osama bin Laden in the summer of 2001 and was sent to the U.S. to help al-Qaida operatives carry out post-Sept. 11, 2001, attacks.

Al-Marri obtained a student visa and returned to the U.S. the day before terrorists crashed two hijacked planes into the World Trade Center and the Pentagon.

More from msnbc.com The climate-fueled march of dengue fever  Were you paying attention? Take our weekly quiz   Analysis: Obama's speech? Take that, Cheney! U.S. officials say top al-Qaida leader killed Credit card debt, terms limit holiday spending  WorldBlog: Chinese activist in Tokyo airport limbo Giving back for the holidays? Send us your pictures

MORE FROM TERRORISM

Terrorism Section Front

Taliban surpasses weakened al-Qaida White House: No flu shots for Gitmo detainees Feds: Chicago men discussed India attack Terrorism Section Front   Add Terrorism headlines to your news reader: