(BOSTON) -- In the hours before Dzhokhar Tsarnaev was charged with the crime that could lead to the death penalty, authorities tell ABC News the 19-year-old accused terrorist has started to provide his version of the events that led to the deadly Boston Marathon bomb attacks.
For all the power of the two explosions at the Boston Marathon finish line, and for all the dramatic gun fights on the streets of Watertown, and for all the suppositions about the role of disciplined, well-trained terrorists, the college student reportedly told investigators the whole attack was devised from the Internet. The two brothers, he said, had no direction or financing from governments or rogue groups overseas.
Authorities tell ABC News they now believe the two foreign-born brothers were inspired to violence by the Internet preachings of al Qaeda leader Anwar Al-Awlaki, the charismatic American-born radical jihadist, who has been dead now for more than a year. They used instructions from an al Qaeda Internet magazine to make their pressure cooker bombs. And Dzhokhar, the younger of the brothers, may not have even known about the plot until a week or so before the attack, sources told ABC News.
Seth Jones, a counter-terror expert at the RAND Corporation, said the attack's simplicity and homegrown origins may wind up being some of the most chilling aspects the Boston bombing.
"This is kind of the al Qaeda modus operandi now, not relying only on operatives, but trying to get people do-it-yourself radicalization to build their own bombs without coming to a training camp in Pakistan or Yemen or other locations," Jones said.
"They ad-libbed part of it and made some decisions on a few elements of the bomb making but what's different about this is they took a very simple recipe and then targeted the Boston Marathon," Jones said. "And why the marathon? Because it was there, essentially, and easy. Not long in the planning."
Authorities also told ABC News it is increasingly likely that the older of the brothers, Tamerlan, devised the plot and did most of the work in pulling it together.
Tamerlan Tsarnaev, 26, died during a firefight with police early Friday morning.
"The older brother appeared to be the more radicalized of the two and was the one that drove the need to conduct the attack as well as the preparation for the attack that is building the bombs," Jones said.
And as to what drove Tamerlan to violence, his younger brother has apparently told investigators it was his hatred of America, and its policies in Afghanistan and Iraq, law enforcement sources said.
What the younger brother is reportedly telling investigators is consistent with what many of those who knew Tamerlan were observing -- his disgust with things American and Christian.
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