Investigators say Shahzad, a 30-year-old American of Pakistani descent, was inspired by Anwar al-Awlaki's rhetoric in Web videos about violent jihad, or Muslim holy war, The New York Times reported.
Shahzad has been charged with terrorism and weapons offenses for an alleged attempt to set off a car bomb in midtown Manhattan. He's accused of parking an SUV loaded with firecrackers, gasoline, propane and fertilizer in Times Square on Saturday evening, rigged to explode into what authorities say could have been a fireball big enough to kill nearby tourists and Broadway theatergoers. Witnesses alerted police to the smoking vehicle before it could explode.
At first, the rudimentary nature of the SUV bomb, with a mess of wires and low-grade fertilizer, led authorities to assume the plot was hatched by an amateur rather than someone with sophisticated al-Qaida training from someone like al-Awlaki.
Over the years, Shahzad has made several trips back and forth to his native Pakistan, where al-Qaida has a strong presence. During that time, he was associated with at least one person who was in contact with al-Awlaki, another unnamed U.S. official told The Washington Post. The Times Square suspect told investigators he'd watched al-Awlaki's online videos, in which he advocates violence against the West, and said he was inspired, a senior law enforcement official told the same newspaper.
Earlier this year, President Barack Obama took the rare step of authorizing al-Awlaki's assassination -- making him the first American citizen on the CIA's hit list. Al-Awlaki's video lectures have turned up in dozens of terrorism investigations.
Al-Awlaki is thought to be a top al-Qaida operative in Yemen. He was linked to the terror group's training of the young Nigerian man accused of trying to blow up a Detroit-bound airliner on Christmas Day. And he's believed to have exchanged e-mails encouraging an American Army doctor and fellow Muslim to open fire on colleagues at Fort Hood in November, killing 13 people.
Authorities are also looking for others who may have had a more direct role in helping Shahzad plan his botched attack. Among them is a money courier accused of helping funnel cash from overseas to help him buy the SUV and explosives, an unidentified official told The Associated Press.
Shahzad paid for the used Nissan Pathfinder with 13 $100 bills, and he was caught on videotape buying fireworks in Pennsylvania -- all with no apparent source of income over the past three months. Investigators know the courier's name but haven't released it, the official said.
That suspect could be key to revealing whether Shahzad's plot was one man's deed, or something possibly funded by terrorist groups abroad.
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Investigators are trying to determine whether any of the money is linked to terrorist groups, an official told the Post.
More details are emerging about how close Shahzad got to escaping from the U.S. before his arrest. He was plucked off a Dubai-bound flight from New York's JFK airport on Monday, moments before take-off.
When U.S. Customs officers boarded the plane and paged Shahzad to the front of the cabin, he calmly unbuckled his seat belt, identified himself and then put his hands behind his back in order to be handcuffed. As he walked down the tarmac, he asked Customs Officer Robert McConkie whether he was with the FBI or NYPD, the officer told ABC News.
McConkie showed him the Customs patch on his sleeve. Shahzad said, according to McConkie: "I was expecting you. I wondered what took so long."