BOSTON (NBC) -- The suspects in the attack on the Boston Marathon - one killed, one on the loose - are brothers of Chechen origin, at least one a legal permanent resident of the United States, law enforcement officials told NBC News.
The suspect at large early Friday was identified as Dzhokhar Tsarnaev, 19, born in Kyrgyzstan and holding a Massachusetts driver's license. He was the suspect in the white hat in surveillance photos from the marathon released by the FBI.
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His brother, who was killed in a firefight with law enforcement, was identified as Tamerlan Tsarnaev, 26, born in Russia. He became a legal permanent resident in 2007, the officials said. He was the suspect in the black hat in the FBI photos.
Both men were believed to have military experience, and to have entered the country with their family in 2002 or 2003. The nature of the military experience was not clear.
The city of Cambridge, Mass., awarded Dzhokhar Tsarnaev a $2,500 scholarship toward college in 2011, according to The Boston Globe.
In 2002, Chechen militants seized a Moscow theater and held 800 people hostage for two days. Special forces raided the building and killed 41 hostage-takers; 129 hostages were killed, mostly from gas used by Russian forces.
Chechnya declared independence during the breakup of the Soviet Union. Russian troops invaded in 1994 and withdrew in 1996.
Tamerlan Tsarnaev was killed after a chaotic chase and firefight with police early Friday. Authorities were conducting a house-to-house search in the Boston suburb of Watertown for his brother.