By Daniel Lovering
BOSTON, July 14 (Reuters) - An FBI agent who interrogated a friend of the accused Boston Marathon bomber charged with obstructing the investigation into the blasts was expected to testify on Monday as the second week of the trial begins.
Azamat Tazhayakov is the first of three friends of Dzhokhar Tsarnaev to face trial on charges of interfering with the investigation by going to the suspect's dorm room and removing a laptop and backpack containing empty fireworks casings three days after the April 15, 2013, attacks.
FBI special agent John Walker led a search of an apartment in New Bedford, Massachusetts, where Tazhayakov lived with fellow Kazakh exchange student Dias Kadyrbayev four days after the bombing attack that killed three people and injured 264. He is scheduled to return to the witness stand for a second day.
Walker has said he was pursuing a lead that Tsarnaev was hiding out at the apartment, but the lead turned out to be false. At the time, the bureau was concerned that other conspirators may have been involved in the bombing plot. Tsarnaev's older brother Tamerlan, also a suspect in the bombing, was killed hours earlier after a shootout with police.
Walker has said he interviewed Kadyrbayev and Tazhayakov, and a third person he described as Kadyrbayev's girlfriend.
Tazhayakov's attorneys argued before the trial that their client's statements during that interview, which began April 19 and ran into the next morning, should not be admitted at trial because he had not believed he was free to go at the time.
Kadyrbayev and Tazhayakov, as well as Robel Phillipos of Cambridge, Massachusetts, have been charged with hindering the probe into the bombing attack.
Tazhayakov could face up to 25 years in prison if convicted of obstruction of justice and conspiracy. Kadyrbayev faces the same charges. Phillipos is accused of the lesser charge of lying to investigators. (Editing by Scott Malone and Doina Chiacu)