Boston Bombing: FBI looking for "person of interest"

From Homeland Security News Wire:

Boston bombing:

  FBI looking for a “person of interest” who may have helped the Tsanaev brothers

 29 April 2013

Lawmakers with knowledge of the investigation into the Boston marathon bombing said over the weekend that law enforcement agencies are looking for a “person of interest” who may have been involved with the Tsarnaev brothers in preparing the attack. The lawmakers highlighted the fact that law enforcement agencies are not convinced that the brothers acted alone, without any help of one or two more people.

• Representative Dutch Ruppersberger (D-Maryland), the ranking Democrat on the House Intelligence Committee, told ABC News on Sunday that the FBI is investigating “persons of interest” who is still in the United States. “There are persons of interest in the United States…. We’re looking at phone calls before and after the bombing, this type of investigation.”
• House Intelligence Committee chairman Mike Rogers (R-Michigan) said on the same new show: , “There are still persons of interest in the United States that the FBI would like to have conversations with…. [But] the big unknown” in understanding the origins of the attack were the six months Tamerlan Tsarnaev spent in Russia. “I think [Russian authorities] have information that would be incredibly helpful that they haven’t provided yet.”
• House Homeland Security Committee chairman Michael McCaul (R-Texas) said on Fox News Sunday that he had discussed the involvement of “trainers” with the FBI. “I think given the level of sophistication of this device, the fact that the pressure cooker is a signature device that goes back to Pakistan, Afghanistan, leads me to believe … that there was a trainer and the question is where is that trainer or trainers,” he said. “Are they overseas in the Chechen region or are they in the United States?” he asked. “In my conversations with the FBI, that’s the big question. They’ve casted a wide net both overseas and in the United States to find out where this person is. But I think the experts all agree that there is someone who did train these two individuals.”
• Representative Adam Schiff (D-California), a member of the House Intelligence Committee, told CNN’s “State of the Union” that he believed the Russians “know more than they’re telling us.” He pointed out that the Russian authorities recorded a conversation between Tamerlan Tsarnaev and his mother (see this New York Times report, and this Daily Mail story), and said he wanted to know why: ‘We don’t know that. We haven’t received that information from the Russians,” he said. “We don’t yet know how exactly the brothers became radicalized, he said, though he said there probably is no link to a major terrorist group. “It does look like a lot of radicalization was self-radicalization online, but we don’t know the full answers yet,” he said.