Dar-al-Hijrah Islamic Center, the mosque in Falls Church, Va., where accused Fort Hood attacker Nidal Malik Hasan worshipped in 2001 when he lived in the Washington, D.C., area, is perhaps best known as the same mosque that three 9/11 hijackers attended prior to flying a plane into the Pentagon.

But according to federal documents, records and terrorism investigators, the mosque also has a history of attendees and members who have had ties to al-Qaeda, Hamas and other radical Islamic groups – including some convicted of terrorism-related crimes.

Hasan, who was charged Thursday with 13 counts of premeditated murder under Article 188 of the Uniform Code of Military Justice in connection with last week's fatal shootings at Fort Hood, had been in contact with the mosque's radical former imam (spiritual leader), Anwar al-Awlaki, before the shootings, according to investigators.

Al-Awlaki, who is the author of "44 Ways to Support Jihad," allegedly praised Hasan's actions from a Web site he runs out of Yemen.

According to the 9/11 Commission report, in 2001, while leader of Dar-al-Hijrah, then-Imam al-Awlaki introduced 9/11 hijackers Nawaf al-Hazmi and Hani Hanjour to another worshipper at the mosque, Eyad al-Rababah, who helped them secure an apartment in Alexandria, Va.

Al-Hazmi and Hanjour, who started attending the mosque in May of that year, joined with a third man who also attended the mosque, a Saudi named Khalid al-Mihdhar to become three of the five hijackers onboard American Airlines Flight 77, which took off from Dulles and was flown into the Pentagon on Sept. 11.

Rababah was later deported to Jordan after being convicted in "a fraudulent drivers' license scheme," according to the 9/11 Commission report.

But apparent links between Dar-Al-Hijrah and radical Islam do not end there:

-- The telephone number of the mosque was discovered in the German apartment of one of the 9/11 co-conspirators, would-be "twentieth hijacker" Ramzi Binalshibh, according to a 2002 joint House-Senate Select Committee on Intelligence report.

In describing the connection to congressional staff, an FBI special agent said, "(T)here's a lot of smoke there."

-- Former mosque attendee AbdulRahman Alamoudi was convicted in 2004 in U.S. District Court in Alexandria, Va., of violating terrorism-related sections of the International Emergency Economic Powers Act by raising money for al-Qaeda from Northern Virginia, according to Treasury Department documents and a Justice Department news release.

Alamoudi was sentenced to 276 months (23 years) in jail for falsifying documents and concealing his financial dealings with entities in Libya, and for recruiting people for a Libyan plot to assassinate Saudi Crown Prince Abdullah.

(His attendance at the mosque was documented in several sources, including a story in the June 9, 2006 Investor's Business Daily.)

-- Another former attendee, Ahmed Omar Abu Ali, is serving a 30-year federal sentence for plotting to assassinate President George W. Bush.

Abu Ali was raised in Falls Church, Va., and according to The Washington Post and The New York Times, taught Islamic studies to children at Dar al-Hijrah in the '90s, before joining a clandestine terrorist cell with ties to al-Qaeda while studying in Saudi Arabia.

Abu Ali received training from members of the al- Qaeda cell in weapons, explosives and document forgery, and discussed plans to smuggle Saudi al-Qaeda members into the United States through Mexico to carry out terrorist operations within the country, according to testimony before the House Homeland Security Committee in 2006 and federal court documents.

(See: "Homeland Security Implications of Radicalization," House Homeland Security Committee, 20 September 2006.")

He was arrested in 2003 in connection with a hotel bombing in Riyadh that left 34 dead, including nine Americans, and told police about his plot against Bush.

"My idea was . . . that I would walk on the street as the president walked by, and I would get close enough to shoot him, or I would use a car bomb. I wanted to be the brain, the planner, just like Mohammed Atta and Khalid Sheikh Mohammad," Ali said to authorities. (Atta and Mohammad were the two lieutenants of Osama bin Laden who planned the Sept. 11 attacks.)

Hamas, Jihad and the War on Terror

Steven Emerson, founder of the Investigative Project on Terrorism, a storehouse of archival data and intelligence on Middle-Eastern terrorist groups, called Dar al-Hijrah "one of the most radical mosques in the United States."

Emerson, a former staff investigator for the Senate Foreign Relations Committee who has supplied information for several congressional hearings on terrorism, said there have been "calls for jihad against the United States coming from that mosque (since) back in the late '90's, plus calls for support of suicide bombings."

"It's been an epicenter for Hamas," Emerson told CNSNews.com. "Most Hamas leaders in the United States, or many of (them), have been centered at that mosque itself," Emerson told CNSNews.com.

According to Justice Department documents, former mosque attendees allegedly have taken roles in Hamas or provided it with funding. Others at the mosque have defended the terrorist group.

-- Mousa Abu Marzook attended the mosque before he was indicted on racketeering charges in 2004 for allegedly filtering money to Hamas. In court papers filed in U.S. District Court, Justice Department prosecutors said Marzook had based himself in Northern Virginia where the mosque is, and had served both as deputy chief and chief of the Hamas Political Bureau in Damascus, Syria. Marzook subsequently fled to Syria.

-- The current imam at Dar-al-Hijrah, Shaker Elsayed told the Associated Press in a 2005 profile that Hamas, which is on the U.S State Department's list of terrorist organizations, was akin to Nelson Mandela's African National Congress.

"Everybody jumps on Hamas," he said. "When did Hamas emerge? 1990 or so? Look at how long Israel has occupied (Palestinian lands.) How long did it take to say enough is enough?"

Elsayed, who was quoted in the same article as saying that Muslims are entitled to use "all force necessary" in responding to those who "kick you off your homeland," served as unofficial spokesman for the family of Abu Ali during his trial, and has made statements in support of other radicals.

"Islam forbids you to give your allegiance to those who kick you off your homeland, and to those who support those who kick you off your homeland," he said while preaching at the mosque, the Associated Press reported.

Elsayed also defended three Muslims from a neighboring Falls Church mosque who were convicted in 2004 of conspiring to aid insurgents in Afghanistan and India by training with paintball guns.

One of the conspirators, Sabri Benkahla, was sentenced to 10 years in prison in 2007 for lying to the FBI about his role in the activity. Justice Department prosecutors termed the group a "Virginia jihad network" and they became more commonly known as the "paintball jihadis."

After the ruling came down, Elsayed, then-secretary-general of the Muslim American Society, said, "It is evident that Muslims should not expect justice. Muslims are besieged after 9/11, for no fault of their own. "

Elsayed was also quoted as saying, "We do have license to respond with all force necessary to our attackers."

-- Meanwhile, an investigation of American mosques performed by the nonprofit human rights group Freedom House, found texts available at the Dar al-Hijrah mosque that promoted the Wahhabi strain of Islam.

Wahhabism is criticized by some Muslims because some of its adherents have committed violent acts against other Muslims who they believe are not true members of the faith.

One of the publications found inside Dar al-Hijrah, was a pamphlet published in Riyadh, which described Zionism as an anti-Islam conspiracy: "Zionism, which is the worst racism in history because of its violence, atrocities, selfishness and arrogance, invests all the means available to it, together with the other enemies, to destroying this religion and exterminating its followers, weakening and paralyzing them to say the least."

(See: "Saudi Publications in Hate Ideology Invade American Mosques," a report from Freedom House.)

A spokesman for the center referred CNSNews.com to a news release openly denouncing former Al-Awlaki. Neither he nor Imam Elsayed would answer questions or comment for this story.

"As we understand the teaching of the scriptures, our mission and method as Americans of faith is to enrich our society with service, wisdom and beautiful preaching of God's love and mercy to all of mankind," the statement said.

"During Mr. Al-Awlaki's short employment at our center, his public speech was consistent with the values of tolerance and cooperation. After returning to Yemen, Mr. Awlaki now claims that the American Muslims who have condemned the violent acts of Major Hasan have committed treason against the Muslim Umaah (community) and have fallen into hypocrisy. With this reversal, Mr. Al-Awlaki has clearly set himself apart from Muslims in America.

"Mr. Awlaki now claims that the American Muslim who have condemned the violent act of Major Hassan 'committed treason against the Muslim Umaah and have fallen into hypocrisy.' With this reversal Mr. Al-Awlaki has clearly set himself apart from this community. He served a brief term of employment at Dar Al-Hijrah from January 2001 until his depart (sic) of April 2002.

"We at Dar Al-Hijrah Islamic Center reiterate our condemnation of this brutal murder. We continue to send our condolences and prayers for the recovery of all the families and victims of this godless act."

"Dar Al-Hijrah Islamic Center is one of the largest and diverse Islamic Centers in the nation. We are committed to serve the community as a place of worship, education and social services."