BOSTON - Boston Marathon bombing suspect Dzhokhar Tsarnaev has told investigators his older brother Tamerlan was the driving force behind last week's attack and that no international terrorist groups were behind them, a U.S. government source told CNN Monday.
Initial interviews with the 19-year-old Tsarnaev indicate the two brothers fit the classification of self-radicalized jihadists, the source told CNN. Dzhokhar Tsarnaev, wounded and held in a Boston hospital, has said his brother -- who was killed early Friday -- wanted to defend Islam from attack, according to the source.
The government source cautioned that the interviews were preliminary, and that Tsarnaev's account needs to be checked out and followed up on by investigators, CNN reported.
The surviving brother was arraigned in his hospital bed, according to ABC affiliate WCVB.
WCVB Reporter Kelley Tuthill tweeted that a federal court official confirmed to her that a magistrate went to Beth Israel Deaconess Medical Center for the first appearance of Dzhokhar Tsarnaev.
Tsarnaev was charged with conspiring with his brother to use a weapon of mass destruction, namely, an improvised explosive device or IED, against persons and property resulting in death, and one count of malicious destruction of property by means of an explosive device resulting in death.
The White House also announced Monday that Tsarnaev wouldn't be tried as an "enemy combatant."
The federal complaint against Tsarnaev goes into great detail about the surveillance videos investigators found from the bombing. It describes the brothers walking through the crowd and Dzhokhar Tsarnaev slipping his backpack to the ground.
The complaint describes Tsarnaev's behavior at the time of the explosion.
"Approximately 30 seconds before the first explosion, he lifts his phone to his ear as if he is speaking on his cell phone, and keeps it there for approximately 18 seconds. A few seconds after he finishes the call, the large crowd of people around him can be seen reacting to the first explosion. Virtually every head turns to the east (towards the finish line) and stares in that direction in apparent bewilderment and alarm. Bomber Two, virtually alone among the individuals in front of the restaurant, appears calm."
The document says Dzhokhar Tsarnaev can be seen glancing east, but "calmly" walks to the west and leaves his backpack behind.
"Approximately 10 seconds later, an explosion occurs in the location where Bomber Two had placed his knapsack," the document said.
ABC News has reported information attributed to law enforcement sources, that the brothers learned how to make the bombs through instructions found on the Internet.
The Associated Press reported that two U.S. officials say the evidence suggests the brothers were motivated by religion and worked alone.
In a section of the federal complaint entitled, "The Bombers Emerge," the document describes the carjacking on April 18 that started the sequence of events that led to Tamerlan Tsarnaev's death and Dzhokhar's capture.
It says the carjacking victim told investigators that one of the brothers pointed pointed a gun at him and said, "Did you hear about the Boston explosion?" and "I did that."
The brother with the gun, it isn't clear which, allegedly forced the victim to drive to another location where the other brother was waiting with something to put into the trunk.
The men demanded money from the carjacking victim, and forced him to give up his ATM card and password. A surveillance camera photo shows Dzhokhar leaving an ATM after allegedly withdrawing money from the carjacking victim's account. The brothers then drove the stolen Mercedes SUV to a gas station where the victim was able to escape.
Sometime later, the stolen car was spotted by Watertown police, leading to the shootout that resulted in a transit officer being seriously wounded and Tamerlan being killed.
Dzhokhar was able to escape that shootout and elude the manhunt for several hours before he was found hiding in a boat stored in a backyard in Watertown, Mass.
Somewhere along the way, Tsarnaevwas shot in the head, neck, legs and hand. As a result, he may never be able to speak again.
Sunday, however, ABC News reported Tsarnaev was "awake and responding sporadically in writing to questions…"
The network said investigators were "asking about other cell members and other unexploded bombs."
The federal complaint also reveals that a large pyrotechnic device and clothing matching the description of the bomber identified as Suspect 2 were found during a search of Dzhokhar Tsarnaev's dorm room at the University of Massachusetts at Dartmouth.
Read the federal complaint against Tsarnaev: http://ch7ne.ws/17T03S2
Read more about the events that led police to the suspects: http://ch7ne.ws/YzaQdj
View a timeline of the hunt on your mobile device: http://ch7ne.ws/15rilKW