The man police and friends say radicalised Roshonara Choudhry was Anwar al-Awlaki, the "spiritual leader" of al-Qaida in the Arabian peninsula (Aqap), who has been linked to multiple attempted plots against the US, by plane and by car bomb.
Choudhry watched online videos of the Islamist cleric, whose sermons were attended by three of the hijackers who carried out the 9/11 attacks. The videos are believed to have helped her to come to the view that she should use violence.
Yesterday Yemeni authorities began a trial in absentia of Awlaki, who is suspected of involvement in the bombs hidden on two cargo planes from Yemen last week. He was accused of plotting to kill foreigners and being a member of al-Qaida.
Awlaki, a US citizen, has also been linked to the failed attempt to blow up a passenger aircraft over Detroit on Christmas Day 2009 using a Nigerian suicide bomber with explosives hidden in his underwear.
US officials say Awlaki is a "recruiter and motivator" for al-Qaida and uses social media to spread his message of violent jihad. US counter-terrorism officials believe the Islamist cleric, who once lived in London, is a prime suspect behind the bombs discovered last Friday, which were sent as cargo on planes, addressed to Jewish groups in Chicago.
Even before then, Awlaki is the only US citizen known to be on the list of targets for assassination by the CIA because of his links to past attacks against the US.
It is a far cry from the time when he was once invited to speak at the Pentagon as part of a defence department outreach programme to Muslims.
Awlakiis linked to the fatal shootings of 13 soldiers at Fort Hood, Texas, by an American Muslim fellow soldier in November 2009.
Awlaki, 39, was born in New Mexico to Yemeni parents. He is believed to have lived in London for 18 months before moving to Yemen in 2004, and is now thought to be in hiding in Yemen's rugged Shabwa or Mareb regions, an area jihadists have at times found to be a safe haven.Suspicion of Awlaki's role in terrorist attacks against the US solidified after it was revealed he was in contact with Nidal Hasan, the US army psychiatrist who carried out the Fort Hood shooting.
Hasan's first email to Awlaki asked if the cleric could justify, under Islamic law, the killing of American soldiers on US soil. The email was sent on 17 December 2008 and was intercepted by the FBI, who failed to stop Hasan before the killings 11 months later. Even after the cleric's contacts with the Fort Hood killer were known, he appeared to be operating freely in Yemen.
Awlaki went on, US officials believe, to play a role in the attempt to bomb a passenger plane in 2009.
Rashad al-Alimi, Yemen's deputy prime minister for defence and security, said Umar Farouk Abdulmutallab, the 23-year-old Nigerian man who tried to detonate explosives aboard an airliner over Detroit, had gone to Awlaki's home during a trip to Yemen late in 2009.
Abdulmutallab arrived in Yemen in late August on a student visa and was last seen on 21 September. He reappeared on 5 December and left Yemen two days later, the authorities confirmed. The deputy minister said that during his 11-week disappearance Abdulmutallab met al-Qaida leaders at a farmhouse at Rafad, in Yemen's eastern province of Shabwa.
Next, Awlaki was linked to Faisal Shahzad, who attempted to bomb Times Square. Shahzad, described by General David Petraeus of US central command as a "lone wolf", has reportedly told law enforcement officials that he was a "fan and a follower" of Awlaki. US officials say the militant preacher is seen as a highly influential figure in mobilising English-speaking Muslims to plan al-Qaida-style atrocities. Al-Awlaki is believed to have lived in London for 18 months before moving to Yemen in 2004.6
