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Boston Ex-Mayor Questions Motives of Some Students

Big Data Download

The still-at-large Boston Marathon bombing suspect, with origins in Chechnya, was a student who hoped to become a doctor, according to his father. But a former mayor of Boston said that the Tsarnaev brothers’ alleged actions show that some who seem to be in the United States in order to study may actually be in the country with other motives in mind."A lot of these students come from foreign countries. And that's fine. But maybe they don't come here at all to be students. Maybe they come here for other things," former Boston Mayor Raymond Flynn told "Big Data Download."

Dzhokhar Tsarnaev, 19, became a U.S. citizen on Sept. 11, 2012, and was enrolled at the University of Massachusetts Dartmouth.

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His older brother, Tamerlan Tsarnaev, 26, who was killed in a shootout with police, studied at Bunker Hill Community College in Boston and wanted to become an engineer, according to a profile that appeared in a Boston University magazine in 2010.

Surveillance cameras show that the two brothers carried backpacks believed to contain the improvised bombs that went off at the marathon.

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Former Mayor Flynn said he asked police why security checks at the marathon didn't involve checking runners' and spectators' backpacks; he said that police responded that those checks would take too much manpower.

"Why is everybody carrying a backback and a huge backpack on their backs?" Flynn asked.

-- Jonathan Dienst and Erin McClam contributed to this story.