At this point in the Boston Marathon bombing investigation, there are many more questions than answers, but they mostly boil down to one in particular:
Did alleged suspects Tamerlan and Dzhokhar Tsarnaev have any outside help, either in the United States or abroad, before setting off two bombs that killed three marathon spectators and wounded more than 260 others.
Officials have said the Tsarnaev brothers were “self-radicalized,” young Muslims influenced by what they learned growing up as the US waged wars in Islamic Iraq and Afghanistan. Whatever outlook they developed likely was crystallized for them via online wanderings through radical websites, then older brother Tamerlan’s six-month visit to Russian republics.
Tamerlan is dead, and Dzhokhar lies wounded in a small cell with a steel door at a federal medical detention center about 40 miles west of Boston. Before he was read his legal rights and stopped talking, the younger brother reportedly told interrogators that the two acted alone.
That may be literally true, but evidence of outside influence in the direction of radical beliefs mounts – including from the brothers’ mother Zubeidat Tsarnaeva.
It was reported Saturday that Russian authorities secretly recorded a telephone conversation in 2011 in which one of the Boston bombing suspects vaguely discussed jihad with his mother.
In a second call, Zubeidat Tsarnaeva spoke with a man in the Caucasus region of Russia who was under FBI investigation, according to the Associated Press. Still, there was no information in the conversation that suggested a plot inside the United States, officials told the AP.
On “Fox News Sunday,” Rep. Rep. Michael McCaul, (R) of Texas and chairman of the House Homeland Security Committee, said he believes the Boston Marathon bombing suspects had some training in carrying out their attack, particularly with the bombs they fashioned.
Rep. McCaul also said he thinks the suspects' mother played "a very strong role" in her sons' radicalization process and that if she were to return to the United States from Russia, she'd be held for questioning.
In recent interviews, Zubeidat Tsarnaeva said she believed her sons were framed by US authorities.
But Ruslan Tsarni, the Tsarnaev brothers' uncle, who immigrated to the United States some years ago, said he believes their mother had a "big-time influence" as her older son increasingly embraced his Muslim faith and decided to quit boxing and school.
Meanwhile, US officials and reporters are probing Tamerlan Tsarnaev’s 2012 trip to Russia’s Caucasus region, including visits to mosques there.
In an interview with Time magazine, Imam Khasan-Khadzhi Gasanaliev was “adamant that his mosque, a bastion of conservative Salafi Islam in Dagestan, had nothing to do with Tsarnaev’s turn to radicalism or with the Boston bombings.”
But his view of US involvement in the world might well have influenced an impressionable young man already unhappy with the country to which his family had immigrated when he was a boy.
“How much has America done in Vietnam, in all its wars everywhere,” the Imam told Time. “Right now it is turning the entire Arab world upside down. They kill hundreds, thousands, millions of people and nobody is interested. But over there someone does something, blows something up, someone is killed, and because of this they send so many people [journalists] here.”
“America will soon collapse. It will disappear,” he said.
Back in the US, Dzhokhar Tsarnaev was moved Friday from a Boston hospital to the Federal Medical Center Devens in Ayer, Massachusetts. His cell has a solid steel door with an observation window and a slot for passing food and medication, facility spokesman John Collauti told the AP.
On Saturday, authorities ended their two-day search of a landfill 60 miles south of Boston, near where Dzhokhar attended college, according to CBS News. Sources say investigators were looking for laptop computers as they try to determine what shaped the Tsarnaev brothers' views.
When Dzhokhar was captured four days after the marathon bombing, he had been seriously wounded in a shoot-out police and was found hiding under the cover of a boat parked in the backyard of a Watertown, Mass., residence.
Authorities have removed the boat as evidence in the case.
A crowd-sourcing site has been established to pay boat owner David Henneberry, but he says, “I'd rather that [the money] go to the One Fund Boston,” to compensate bombing victims.
“To buy me a new boat is a wonderful thing,” he told CNN. “I don't want that, really. I would wish that they donate it to the One Fund Boston. They lost limbs. I lost a boat.”