Boston Marathon Bombing: Investigators Trying to Piece Together Life of Tamerlan Tsarnaev

April 28, 2013— -- Federal investigators are hoping several clues, including a Russian wiretap and a laptop, will be key to helping them piece together the life of Tamerlan Tsarnaev, the deceased Boston Marathon bombing suspect.

The conversations between Tamerlan Tsarnaev and his mother were recorded in 2011 and gave Russian officials concern, however the specifics weren't revealed to U.S. officials until this week, sources told ABC News.

"This tapes are potentially important if there's more to them then has been publicly released," said Brad Garrett, a former FBI special agent and ABC News analyst.

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Authorities spent several days searching for Tamerlan Tsarnaev's laptop in a New Bedford landfill near the University of Massachusetts Dartmouth campus, where younger brother Dzhokhar Tsarnaev attended college, sources told ABC News.

It was unclear if investigators found the laptop, however sources told ABC News authorities found a cell phone believed to belong to Tamerlan Tsarnaev in a nearby apartment.

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Another focus of the investigation has been on a mysterious man named Misha, the person who reportedly influenced Tamerlan or possibly even radicalized him.

The suspects' mother, Zubeidat Tsarnaeva, told ABC News Misha knew a lot about Islam and that it was interesting to learn from him, but denied his views were extreme.

"Nonsense. He was just a friend," Tsarnaeva said earlier this week before she sat down with FBI investigators for a second day of interviews in Dagestan, in southern Russia.

She said their relationship with Misha, an Armenian with a red beard whose identity and full name remain a mystery, was short because he moved to another part of the United States. She did not say where.

Tsarnaeva has denied her sons had a role in the bombing. Her eldest son, Tamerlan, was killed after a shootout with police on April 19, sparking an unprecedented manhunt for 19-year-old Dzhokhar, who managed to escape and was later found hiding in a boat parked in the backyard of a Watertown, Mass., home.

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Dzhokhar Tsarnaev was moved from a hospital to the Federal Medical Center Devens in Ayer, Mass., on Friday.

Spokesman John Collauti told the Associated Press that Tsarnaev was being held in a cell with a solid steel door, an observation window and a slot for passing food and medication.

"Really this type of facility is fully capable of handling him and it's not that much of an inconvenience because it's more or less business as usual," Collauti said.

Meanwhile, along Boylston Street, the site of the bombing, it was a return to normal this weekend with stores open for business.

But the weekend wasn't without a touch of sadness and a reminder of the tragedy that shook the city.

At what would've been 8-year-old Martin Richard's first Little League game of the season, people wore jerseys bearing his name -- a reminder of the youngest life lost in the bombing.

ABC News' Pierre Thomas and Kirit Radia contributed reporting.