President Obama was briefed Saturday on the nascent investigation into the motivations of the two brothers suspected of orchestrating the Boston Marathon bombings.

At a White House meeting of the president's National Security Council, the administration's top intelligence, law enforcement and counter-terrorism officials updated Obama on Friday night's capture of Dzhokhar Tsarnaev, the younger suspect, and the ongoing probe to discover what might have inspired the attacks. 


Among those briefing the president were National Security Advisor Tom Donilon, U.S. Attorney General Eric HolderEric Himpton HolderChristie, Pompeo named co-chairs of GOP redistricting group Democrats look to state courts as redistricting battle heats up On The Trail: Census kicks off a wild redistricting cycle MORE, FBI Director Robert Mueller and Secretary of Homeland Security Janet Napolitano, the White House said. 

Vice President Biden joined the 90-minute meeting by teleconference, the administration added.

Dzhokhar Tsarnaev and his brother, Tamerlan, were ethnic Chechens who immigrated to the United States years ago. Dzhokhar Tsarnaev, who was captured Friday night after a long manhunt, was reportedly made a naturalized citizen last September; Tamerlan Tsarnaev, who was killed Friday morning in a shootout with police, reportedly had a green card.

The brothers' long stay in the U.S., combined with the seeming absence of red flags that might have foreshadowed a terrorist conspiracy, has left law enforcers in and out of the administration scratching their heads in search of why the suspects might have bombed Boston.

Reports on Sunday said investigators were turning their attention to a trip Tamerlan took to Chechnya and Dagestan, Muslim republics in Russia long plagued by Islamist violence. The elder brother spent six months in the region in 2012.

“It’s a key thread for investigators and the intelligence community to pull on,” said Kevin R. Brock, a senior FBI official to the New York Times. 

But officials said it was too early to speculate about their motives, noting that Tamerlan had sought American citizenship and expressed hopes of boxing for the U.S. Olympic Team.

 Obama on Friday night vowed to get to the bottom of that enigma.

"Why did young men who grew up and studied here, as part of our communities and our country, resort to such violence? How did they plan and carry out these attacks, and did they receive any help?" Obama said. 

"The families of those killed so senselessly deserve answers.” 

This story was posted on April 20 at 4:22 p.m. and has been updated.