Boston Marathon bombing suspect Tamerlan Tsarnaev flew in and out of John F. Kennedy Airport last year and was out of the country for six months, and investigators said they want to know if he received any terror training while he was overseas, NBC 4 New York has learned.

Travel records obtained by NBC 4 New York show Tsarnaev left New York on Jan. 12, 2012 for Sheremetyevo, Russia. He stayed overseas and returned to JFK on July 17.

The travel documents show a photo of a bearded Tsarnaev. The documents show the terror suspect was born on Oct. 21, 1986 and first entered the U.S. through JFK on July 19, 2003.

The documents show it was not until Friday that U.S. officials determined he was “a person or instrument that may pose a threat to the security of the United States.”

Tsarnaev was killed amid the shootout with police early Friday. His brother, Dzhokhar Tsarnaev, was taken into custody Friday night after an intense manhunt in Watertown, a suburb of Boston.

Dzhokhar Tsarnaev was born on July 22, 1993, the records show. They also said he flew to the U.S. on April 12, 2002 with his family, which applied for asylum. The family was granted legal permanent residence on March 2, 2007, and Tsarnaev became a citizen on Sept. 11, 2012.

The documents show there is no record of Dzhokhar Tsarnaev leaving the United States.