Questions begin for FBI over Boston

People wave US flags and cheer as police drive down Arlington Street in Watertown, Massachusetts on Friday following the capture of the second suspect in the Boston Marathon bombing, Dzhokhar Tsarnaev Image copyright Reuters
Image caption Relief at the capture of Dzhokhar Tsarnaev, is being followed by serious questions for the FBI

The relief was palpable in a city where 19 April 2013 had been cancelled, paralysed, because of the manhunt for a terrorist.

When the news broke that the second suspect had been caught Boston residents who'd been cooped up under a day-long curfew poured onto the streets whooping with joy.

In one big bar in the Back Bay area, the multiple giant screens usually tuned into various sports channels had all been switched to news channels following the manhunt. People cheered and clapped as the capture was announced.

When President Obama spoke, the normal level of chatter returned and no-one seemed to be paying much attention. But he had something important to say.

"Obviously, tonight there are still many unanswered questions. Among them, why did young men who grew up and studied here, as part of our communities and our country, resort to such violence?

"How did they plan and carry out these attacks, and did they receive any help? The families of those killed so senselessly deserve answers. The wounded, some of whom now have to learn how to stand and walk and live again, deserve answers."

The president might be wise to start by asking President Putin. I have no evidence that the "foreign government" asking questions about Tamerlan Tsarnaev was Russia, but that is my strong suspicion.

Whoever it was, they warned the FBI that Tamerlan was a strong supporter of radical Islam. The FBI say they investigated, interviewed him, and found no links with terrorism. This is quite remarkable. Let me repeat it. The FBI had been warned that the man who apparently carried out the first terrorist attack on an American city since 9/11 was a strong supporter of radical Islam.

People will want to know how far they delved, how hard they tried, how seriously they took the information. Some of the criticism will be unfair, based on hindsight - they must get thousands of such warnings every year. Or perhaps they are quite rare. That is another question.

America has been in a kind of limbo while the identity of the bombers was unknown. With greater certainty the questions, and the politics, will begin.