Why didn't Feds follow up more on Tsarnaev?

Tamerlan Tsarnaev: Former friend describes shock of knowing suspect
Tamerlan Tsarnaev.

(CBS News) BOSTON - Almost two weeks ago, two bombs shattered a scenic celebration at the Boston Marathon. The investigation led to two suspects: One dead, the other in jail. But it's also leading to more questions about the suspects, their family and how much was known beforehand.

The suspects' parents remain in Russia. Their father, Anzor Tsarnaev, is in an undisclosed hospital being treated for high blood pressure. Their mother says she's concerned she would be arrested if she set foot in the U.S.

Her concern stems in part from secret recordings Russian intelligence made of Zubeidat Tsarnaev talking with her older son, Tamerlan, in 2011, during which the term "jihad" was used.

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Russian intelligence officers asked both the FBI and CIA to investigate her son's extremist tendencies that same year.

But when the FBI found Tsarnaev had no terrorist ties, U.S. officials took no further action.

Sen. Lindsey Graham, R-SC, said on "Face the Nation" a U.S. counterterrorism task force received another tip about Tamerlan Tsarnaev when he returned from Russia nine months ago. Graham said the signs were ignored.

"So, it's a failure to share information and miss obvious warning signs," said Graham. "We're going back to the pre-9/11 stove piping."

"When somebody in the database like this begins to interact with radical Islamist websites, an FBI agent should knock on his door and say, 'You told us before you wanted to be an Olympic boxer, you love this country. What the hell is going on here? We're watching you,'" he added.

Former Director of Terrorist Studies at West Point, James Forest, said there are simply too many signs about too many people.

"They call it a 'Watch List' but it's really a database. You have a database with 5,000 names on it ... a database is not a crystal ball," he said.

As Boston continues to resume normal life, hundreds of runners turned out for an annual mini-marathon. Race Director Mark Connell said proceeds will be donated to the "One Fund Boston" for bomb attack victims.

"You can live life being concerned about what might happen or you can live life," he said. "We've decided to live life."

There are those in Congress, including the chairman of the House Intelligence Committee, Mike Rogers, who say Russia needs to cooperate more fully in the investigation. One question they want answered is if Tamerlan Tsarnaev received bomb-making lessons during his six-month trip in Russia.