US army psychiatrist Major Nidal Malik Hasan, who carried out the massacre of 13 fellow US soldiers in Texas, worshipped at a mosque led by a radical imam said to be a "spiritual adviser" to three of the hijackers who attacked America on Sept 11, 2001, The Sunday Telegraph, London reported.
Hasan attended the controversial Dar al-Hijrah mosque in Great Falls, Virginia, in 2001 at the same time as two of the September 11 terrorists, the newspaper report said. His mother's funeral was held there in May that year.
The preacher at the time was Anwar al-Awlaki, an American-born Yemeni scholar who was banned from addressing a meeting in London by video link in August because he is accused of supporting attacks on British troops and backing terrorist organisations.
Hasan's eyes "lit up" when he mentioned his deep respect for al-Awlaki's teachings, according to a fellow Muslim officer at the Fort Hood base in Texas, the scene of Thursday's horrific shooting spree.
As investigators look at Hasan's motives and mindset, his attendance at the mosque could be an important piece of the jigsaw. Al-Awlaki moved to Dar al-Hijrah as imam in January, 2001, from the west coast, and three months later the September 11 hijackers Nawaf al-Hamzi and Hani Hanjour began attending his services. A third hijacker attended his services in California.
Hasan was praying at Dar al-Hijrah at about the same time, and the FBI will now want to investigate whether he met the two terrorists.
Charles Allen, a former under-secretary for intelligence at the Department of Homeland Security, has described al-Awlaki, who now lives in Yemen, as an "al-Qaeda supporter, and former spiritual leader to three of the September 11 hijackers... who targets US Muslims with radical online lectures encouraging terrorist attacks from his new home in Yemen".
Saturday night Hasan remained in a coma under guard at a military hospital in San Antonio, Texas, and was said to be in a "stable" condition. Born in America to a Palestinian family, Hasan, 39, was an army psychiatrist who had chosen to sign up for the US military against his parents' wishes.
But he turned into an angry critic of the wars America was waging in Iraq and Afghanistan and had tried in vain to negotiate his discharge.
He counselled soldiers returning from the front line and told relatives that he was horrified at the prospect of a deployment to Afghanistan later this year – his first time in a combat zone.
Whether due to his personal convictions, his stress over his deployment or other reasons, Hasan is alleged to have snapped and gone on a murderous rampage with a powerful semi-automatic handgun after shouting "Allahu Akhbar" ("God is great"), according to survivors. He had earlier given away copies of the Koran to neighbours.
Investigators at this stage have no indication that he planned the attacks with anyone else. But they are trawling through his phone records, paperwork and computers he used before the attack during an apparently sleepless night.
Five of the 13 victims were fellow mental health professionals from three units of the army's Combat Stress Control Detachment, it was disclosed yesterday.
It is understood that Hasan had been due to be deployed with members of those units in coming months. Whether he deliberately singled out other combat stress counsellors is another key question.
What does seem clear is that the army missed an increasing number of red flags that Hasan was a troubled and brooding individual within its ranks.
"I was shocked but not surprised by news of Thursday's attack," said Dr Val Finnell, a fellow student on a public health course in 2007-08 who heard Hasan equate the war on terrorism to a war on Islam. Another student had warned military officials that Hasan was a "ticking time bomb" after he reportedly gave a presentation defending suicide bombers.
Kamran Pasha, the author of Mother of the Believers, a new novel relating the story of Islam from the perspective of Aisha, Prophet Mohammed's wife, was told of the al-Awlaki connection from a Muslim friend who is also an officer at Fort Hood. Using the name Richard, the recent convert to Islam described how he frequently prayed with Hasan at the town mosque after Hasan was deployed to Fort Hood in July. They last worshipped together at predawn prayers on the day of the massacre when Hasan "appeared relaxed and not in any way troubled or nervous".
But Richard had previously argued with Hasan when he said that he felt the "war on terror" was really a war against Islam, expressed anti-Jewish sentiments and defended suicide bombings.
"I asked Richard whether he believed that Hasan was motivated by religious radicalism in his murderous actions," Mr Pasha said.
"Richard, with great sadness, said that he believed this was true. He also believed that psychological factors from Hasan's job as an army psychiatrist added to his pathos. The news that he would be deployed overseas, to a war that he rejected, may have pushed him over the edge.
"But Richard does not excuse Hasan. As a Muslim, he finds Hasan's religious perspectives to be fundamentally misguided. And as a soldier, he finds Hasan's actions cowardly and evil."
Fellow Muslims in the US armed forces have also been quick to denounce Hasan's actions and insist that they were the product of a lone individual rather than of Islamic teachings. Osman Danquah, the co-founder of the Islamic Community of Greater Killeen, said Hasan never expressed anger toward the army or indicated any plans for violence.
But he said that, at their second meeting, Hasan seemed almost incoherent.
"I told him, 'There's something wrong with you'. I didn't get the feeling he was talking for himself, but something just didn't seem right."
He was sufficiently troubled that he recommended the centre reject Hasan's request to become a lay Muslim leader at Fort Hood.
Hasan had, in fact, already come to the attention of the authorities before Thursday's massacre. He was suspected of being the author of internet postings that compared suicide bombers with soldiers who throw themselves on grenades to save others and had also reportedly been warned about proselytising to patients.
At Fort Hood, he told a colleague, Col Terry Lee, that he believed Muslims should rise up against American "aggressors". He made no attempt to hide his desire to end his military service early or his mortification at the prospect of deployment to Afghanistan. "He had people telling him on a daily basis the horrors they saw over there," said his cousin, Nader Hasan.
Yet away from his strident attacks on US foreign policy, he came across as subdued and reclusive – not hostile or threatening. Soldiers he counselled at the Walter Reed hospital in Washington praised him, while at Fort Hood, Kimberly Kesling, the deputy commander of clinical services, remarked: "Up to this point, I would consider him an asset."
Relatives said that the death of Hasan's parents, in 1998 and 2001, turned him more devout. "After he lost his parents he tried to replace their love by reading a lot of books, including the Koran," his uncle Rafiq Hamad said.
"He didn't have a girlfriend, he didn't dance, he didn't go to bars."
His failed search for a wife seemed to haunt Hasan. At the Muslim Community Centre in the Washington suburb of Silver Spring, he signed up for an Islamic matchmaking service, specifying that he wanted a bride who wore the hijab and prayed five times a day.
Adnan Haider, a retired professor of statistics, recalled how at their first meeting last year, a casual introduction after Friday prayers, Hasan immediately asked the academic if he knew "a nice Muslim girl" he could marry.
"It was a strange thing to ask someone you have met two seconds before. It was clear to me he was under pressure, you could just see it in his face," said Prof Haider, 74, who used to work at Georgetown University in Washington. "You could see he was lonely and didn't have friends.
"He is working with psychiatric people and I ask why the people around him didn't spot that something was wrong? When I heard what had happened I actually wasn't that surprised."
Indeed, many of the characteristics attributed to Hasan by acquaintances – withdrawn, unassuming, brooding, socially awkward and never known to have had a girlfriend – have also applied to other mass murderers.
Hasan was born and brought up in Virginia to parents who ran restaurants after emigrating to America from the West Bank. He graduated from Virginia Tech university – coincidentally, the scene of the worst mass shooting in US history in 2007 – with a degree in biochemistry and then joined the army, which trained him as a psychiatrist.
Relatives said that he was subjected to increasingly ugly taunts about his religion and ethnicity from other soldiers after the September 11 attacks. But his uncle insisted yesterday that Hasan would not have been driven to mass murder by revenge or religion.
Speaking in the West Bank town of al-Bireh, Mr Hamad said his nephew "loved America" and could only have been caused to snap by an as yet unexplained factor. "He always said there was no country in the world like America," he told The Sunday Telegraph. "Something big happened to him in Texas. If he did it – and until now I am in denial – it had to have been something huge because revenge was not in his nature."