WASHINGTON/BOSTON (Reuters) – The two men accused of carrying out last week’s bombing of the Boston Marathon planned a second bomb attack on New York’s Times Square, according to law enforcement and national security sources.

The sources said brothers Tamerlan and Dzhokhar Tsarnaev’s original intent when they hijacked a car and its driver in Boston last Thursday night was to drive to New York with seven bombs and detonate them, but their plan fell apart when they became embroiled in a shootout with police.

WASHINGTON (Reuters) – An FBI-led Joint Terrorism Task Force in Boston was alerted when one of the men who later allegedly carried out the Boston Marathon bombings traveled to Russia, U.S. officials said on Wednesday in one of several disclosures that cast new light on the government’s handling of the case.

The officials also said Russia, which had tipped off the FBI about its concerns over one of the men, Tamerlan Tsarnaev, in early 2011, made a second, identical request to the CIA in late September 2011.

WASHINGTON (Reuters) – The name of one of the Boston Marathon bombing suspects, Tamerlan Tsarnaev, was listed on the U.S. government’s highly classified central database of people it views as potential terrorists. But the list is so vast that this did not mean authorities automatically kept close tabs on him, sources close to the bombing investigation said on Tuesday.

Tsarnaev, 26, was killed in a police shootout early Friday, while his younger brother Dzhokhar, 19, was captured later that day. Prosecutors say the brothers, ethnic Chechens who had been living in the United States for more than a decade, planted two bombs that exploded near the finish line of the marathon on April 15, killing three people and wounding more than 200.

WASHINGTON (Reuters) – U.S. investigators are trying to trace the contacts and movements in the United States of Chiheb Esseghaier, a Tunisian doctoral student in Canada who is one of two suspects arrested by Canadian authorities for allegedly plotting to derail a passenger train.

Sources close to the investigation said on Tuesday that Esseghaier, a Montreal resident, had made several trips to the United States. U.S. investigators are now trying to locate and check out people he might have met, the sources said.

WASHINGTON (Reuters) – U.S. lawmakers asked on Sunday why the FBI had failed to spot the danger from one of the Boston Marathon bombing suspects, and they complained it was one of a series of cases in which someone the agency had investigated had later taken part in attacks.

House of Representatives Homeland Security Committee Chairman Michael McCaul wrote to the FBI and other officials asking why Tamerlan Tsarnaev did not raise suspicions after Russia asked the bureau to investigate him two years ago.

WASHINGTON (Reuters) – Russia asked the FBI in early 2011 to investigate Boston bombing suspect Tamerlan Tsarnaev out of concern he had embraced radical Islam and was going to travel to Russia to join underground groups, U.S. law enforcement sources said on Saturday.

Russia’s Federal Security Service, or FSB, made a request for checks on Tsarnaev – who was killed after a shootout with police on Thursday – to help an investigation of its own, a U.S. government source said.

WASHINGTON (Reuters) – The FBI in 2011 interviewed one of the brothers suspected in the deadly Boston Marathon bombings, a U.S. law enforcement source said on Friday, a disclosure that could raise questions about whether the government missed potential warning signs about the men’s behavior.

The source said the FBI’s dealings two years ago with Tamerlan Tsarnaev occurred following a request from an unidentified foreign government.

By Mark Hosenball

(Reuters) – Investigators are seeking to locate and talk to at least two men pictured in images taken before two bombs exploded near the finish line of the Boston Marathon, law enforcement and national security officials said on Thursday.

Authorities are examining thousands of pictures taken by surveillance cameras, the media and ordinary citizens around the time the bomb blasts went off and are likely to try to talk to additional people, the officials said.

BOSTON/WASHINGTON, April 17 (Reuters) – Investigators have spotted a Boston
Marathon bombing suspect from security video taken before two blasts ripped
through central Boston on Monday, a U.S. law enforcement source said on
Wednesday, in what is potentially the biggest break in the case yet.

No arrests had been made, and the suspect in the video had not been
identified by name, two U.S. government officials said. Police may make an
appeal to the public for more information at a news conference scheduled for
later on Wednesday, a U.S. government source said.

WASHINGTON/BOSTON (Reuters) – U.S. investigators led by the FBI are poring over video and photographs from the widely watched Boston Marathon for clues to determine who is responsible for two bombs that exploded near the finish line on Monday, killing three people and injuring more than 100, officials said.

Because the Boston Marathon is run by 27,000 people and some 500,000 come to watch every year, officials expect plenty of visual evidence into what happened before and after two devices exploded as hundreds of runners streamed to the finish line at Copley Plaza in Boston’s Back Bay neighborhood.