Lawmaker: Russians would have ‘offed’ Tsarnaev if they’d known of visit

“I presume that means they'd have offed him, which would have been great.”

Mueller said that U.S. officials didn’t let Russia know about Tamerlan returning to Dagestan, “because we did not pick that up.”

The FBI task force that had been investigating Tsarnaev in 2011 got the notice in 2012 that he had left the United States, said Mueller. But because the case had been closed, the task force did not act on the notice.

As a result, Mueller said that the FBI has revamped its protocols so that any notice of a suspect, even if the case has been closed, is physically recorded and not carried out informally.

Congress does not need to pass any new laws to fix the issue, he testified before the House Judiciary Committee on Thursday.

Mueller told lawmakers that after the Russians initially notified them in 2011 about Tsarnaev, the FBI did a thorough investigation.

He said investigators interviewed a number of people, including Tsarnaev, but did not find evidence to justify wiretapping the U.S. resident. He said the FBI then asked the Russians three separate times to turn over more information.

“We got no response from them,” said Mueller on Thursday.

Mueller says there has been a “chilly period” with the Russian intelligence service, but that after the bombing in Boston they helped the U.S. in their investigation.