Feds Search Landfill for Boston Suspect's Laptop

April 26, 2013— -- Investigators in white hazmat suits are searching a landfill for a laptop tied to the accused Boston Marathon bombers, a potential lead that emerged as a result of interviews with two men from Kazakhstan who knew the terror suspects, law enforcement sources told ABC News.

Immigration officers arrested the two men, Dias Kadyrbayev, 19, and Azamat Tazhayakov, 20, on Saturday on suspicion that they had violated the terms of their student visas because they were no longer attending classes. They are being detained on the administrative charges at the Suffolk County (Mass.) House of Corrections.

The men lived in an apartment near the campus of University of Massachusetts Dartmouth, where accused bomber Dzhokhar Tsarnaev, 19, had been enrolled as a student. Both Tsarnaev brothers were believed to have visited the New Bedford apartment of Kadyrbayev and Tazhayakov after the bombing, according to three law enforcement sources, who spoke on the condition they not be named because they were discussing an ongoing investigation. The police sources told ABC News they traced calls and Russian language text messages from one of the bombing suspect's cell phone to the Kazakhstani men.

It was through the Kazakhstani men that investigators learned of the possible whereabouts of Tamerlan Tsarnaev's laptop and authorities have been searching the New Bedford landfill for the past three days, the police sources told ABC News. And, the sources said, agents found a cell phone believed to belong to Tamerlan Tsarnaev's in the New Bedford apartment.

One of the New Bedford men drove a BMW with a vanity plate that read "TERRORISTA #1" on the front, which his father told reporters was an unfortunate joke gift from some friends in Spain.

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Azamat's father, Murat Kadyrbayev told reporters that the two young Kazakhs are simply in Tsarnaev's social circle, according to a report in the New Bedford-area newspaper South Coast Today. "They knew Tsarnaev and hang around together sometimes," he said, maintaining they "were questioned only as witnesses."

Tsarnaev and the two Kazakhstani men posed in a photograph together while on a trip to New York's Times Square, a photo that has attracted attention since Thursday, when New York officials said they learned that Times Square was allegedly the Tsarnaev's next target.

New York police say Times Square narrowly missed being attacked by the accused Boston bombers, with the surviving suspect allegedly telling interrogators that he and his brother made a spontaneous decision to continue trying to maim and kill Americans.

"He told the FBI apparently that he and his brother had planned to drive to New York and detonate additional explosives in Times Square," New York Mayor Michael Bloomberg said at an afternoon City Hall press conference.

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But New York was spared, officials say, at the moment the two accused bombers realized the Mercedes they carjacked in Cambridge needed gas.

"The driver used the opportunity to escape and call the police that led to the shootout in Watertown," said New York Police Commissioner Ray Kelly.