Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
Will Maine enforce quarantine on nurse who treated Ebola patients?
Democratic Congressman Bill Keating of Massachusetts sent staff to Russia to investigate Boston bombing suspect Tamerlan Tsarnaev's alleged ties to extremists.
"What they found out was that, indeed, Tamerlan had contact with two insurgents, two people that were members of an insurgency there, in the Caucuses Region," said Keating.
Tsarnaev made contact with William Plotnikov and Mahmoud Nidal, said Keating. Plotnikov was a boxer in Canada, someone Tsarnaev had known from his days in the boxing ring.
The two of them were already planning a meeting in Russia, said Keating. Tsarnaev met Nidal later in Dagestan.
According to the congressman's non-governmental sources, Russian intelligence previously questioned Plotnikov, who gave up names of other individuals – one of them was Tamerlan Tsarnaev.
"That prompted the Russians to put him on the radar," said Keating. "They saw jihadist websites and they saw him there. That's when we were led to believe they contacted the U.S."
Russia and the United States had a mutual security interest in Tsarnaev. But there is "huge historic distrust" between the United States and Russia, said Keating, left over from the Cold War era. That distrust may have led the United States to question Russia's warning.
When Poltnikov and Nidal were killed in raids, Tsarnaev returned to the United States.
"We knew there were insurgents [in the Caucasus Region], and terrorists being trained there. We knew that. But until recently and, clearly, until Boston ... we thought that that was directed just at the Russians," said Keating.
"Now we know that it also includes Western Europe and it includes the United States," said Keating.
Boston Police Commissioner Ed Davis testified before the House Homeland Security Committee on Thursday, saying his force was not aware of Russian intelligence warning the United States about Tsarnaev travelling overseas to meet with extremists.
"We were not, in fact, informed of that particular development," said Davis.
Davis cautioned that this is all in hindsight, and even if the department had that information, it may not have made a difference.
"Whether or not it would have made a difference isn't our real issue," Keating told CNN. "Our issue is, if there are gaps in intelligence, if there's not information sharing and there should be, that's got to be corrected."