Authorities say the Boston Marathon bombing suspects, Tamerlan and Dzhokhar "Johar" Tsarnaev, appear to have been motivated by their Islamic faith but not connected with any Muslim terrorist groups.
The new information comes as officials begin questioning the younger suspect, Johar. From his hospital bed, the 19-year-old told authorities he built the pressure cooker bombs almost entirely from directions on the Internet, with no help from terrorists overseas.
"I would characterize it as really self-radicalization. These are individuals who may have some connections overseas, but the primary radicalization is in places like the United States," Seth Jones, a political scientist at the RAND Corporation, explained.
Still, authorities believe al Qaeda and the preaching of radical jihadist Anwar al-Alawlaki may have inspired the two.
Investigators are looking closely at the older brother, Tamerlan, as the possible brains behind the attack. Of particular interest: his six-month trip to Russia and Chechnya last year.
As CBN News's George Thomas recently reported, Chechnya has been a volatile region, a place of numerous clashes between Muslim militants and Russian forces. It's also served as a training ground for militants dedicated to the global jihad.
Neighbors say when Tamerlan returned from his trip, his views were more extreme and he expressed anger about America and Christianity.
"He said that the Bible was a cheap copy of the Koran. He said that most American wars are excused with the Bible," one neighbor recalled.
A Boston-area mosque also reports outbursts from Tamerlan during services in November and January, where he argued against celebrating American holidays and criticized civil rights leader Dr. Martin Luther King, Jr.
Meanwhile, more hard evidence is also emerging against the brothers. FBI court papers indicate that one of them told a car-jacking victim, "Did you hear about the Boston explosion? I did that."
In the midst of the investigation, Boston is moving on. Hundreds turned out for a memorial service Monday for 23-year-old Lingzi Lu, one of three killed in last Monday's blasts.
Of the more than 200 victims, 48 are still recovering in the hospital. But doctors say all are expected to survive.
As for the accused bomber, he's been charged with federal crimes that could bring the death penalty.