Just remember that the Boston bombers were "homegrown" terrorists and religion had nothing to do with their actions.

Time Magazine:

Last year, when Tamerlan Tsarnaev spent six months in the Russian region of Dagestan, he had a guide with an unusually deep knowledge of the local Islamist community: a distant cousin named Magomed Kartashov. Six years older than Tsarnaev, Kartashov is a former police officer and freestyle wrestler -- and one of the region's most prominent Islamists.

In 2011, Kartashov founded and became the leader of an organization called the Union of the Just, whose members campaign for Shari'a and pan-Islamic unity in Dagestan, often speaking out against U.S. policies across the Muslim world. The group publicly renounces violence. But some of its members have close links to militants; others have served time in prison for weapons possession and abetting terrorism -- charges they say were based on fabricated evidence. For Tsarnaev, these men formed a community of pious young Muslims with whom he could discuss his ideas of jihad. Tsarnaev's mother Zubeidat confirmed that her son is Kartashov's third cousin. The two met for the first time in Dagestan, she said, and "became very close."

The Islamist was interviewed by Russian security and told the same story as others who have been interviewed in the region; Tamerlan Tsarnaev was interested in global jihad:

Kartashov told the FSB roughly the same story, Abdullaeva says, and it matches the accounts of five other men in Dagestan who know Kartashov and spent time with Tsarnaev. All of them dismiss the notion that Tsarnaev was radicalized in Dagestan. Instead, the picture that emerges from their accounts is of a young man who already carried a deep interest in Islamic radicalism when he went to Russia from his home in Massachusetts. But that curiosity evolved during his visit. The members of Kartashov's circle say they tried to disabuse Tsarnaev of his sympathies for local militants. By the end of his time in Dagestan, Tsarnaev's interests seem to have shifted from the local insurgency to a more global notion of Islamic struggle -- closer to the one espoused by Kartashov's organization.

The younger Tsarnaev may have gravitated to his brother's idea of jihad gradually, but however it happened, Dzhokhar Tsarnaev was a full fledged radical by the time they carried out the attack.

Authorities may not even bring up the radicalization of the Tsarnaevs during the trial, choosing instead to focus on their inability to assimilate as immigrants or some other non-germane reason for the attack.

Meanwhile, the FBI continues to investigate the brothers and the more they look into their past, the more it appears that extremist ideology animated their actions. Whether they will find accomplices here in the US is still not known, but it seems clear that Islamists in Dagestan knew what kind of man Tamerlan Tsarnaev was and what he was capable of.