They waived bail requests until a later court date. At one point, Magistrate Judge Marianne Bowler admonished Phillipos, "I suggest you pay attention to me, rather than looking down."
Tazhayakov and Kadyrbayev appear in a photograph with Dzhokhar Tsarnaev taken in New York's Times Square during an earlier visit. They were taken into custody last month on charges that they had violated the terms of their student visas, Kadyrbayev attorney Stahl said last week.
All three were questioned at length on April 19, when the manhunt for Tsarnaev was in full swing. Tsarnaev's brother Tamerlan had been killed in a gun battle with police early that morning, while Tsarnaev was captured alive but badly wounded that night. Dzhokhar Tsarnaev is being treated for gunshot wounds at a federal Bureau of Prisons medical center in Devens, Massachusetts.
About a month before the marathon attack, Tsarnaev had told Kadyrbayev and Tazhayakov "that he knew how to make a bomb," according to an FBI affidavit recounting the charges. Kadyrbayev told investigators that Tsarnaev "appeared to have given himself a short haircut" two days after the bombings.
Kadyrbayev's lawyer Robert Stahl said his client "did not have anything to do" with the bombing and disputed charges that he tried to obstruct the investigation. And Harlan Protass, who represents Tazhayakov, said his client "has cooperated fully with the authorities and looks forward to the truth coming out in this case."
On Wednesday, he said Kadyrbayev was accused of a "technical violation" of a student visa "for not regularly attending classes." Federal law enforcement sources said at the time that the Kazakh students were being detained "in an abundance of caution" because authorities wanted detailed information on the Tsarnaevs' movements in the weeks and days before the attack.
Phillipos faces up to eight years in prison if convicted, along with a $250,000 fine; the charges against Kadyrbayev and Tazhayakov carry sentences of up to five years and $250,000 in fines.
Alan Dershowitz, a prominent defense attorney and Harvard law professor, called the obstruction charge "weak," suggesting it was meant to pressure the suspects into providing more information on Tsarnaev.
"If that's the best the feds have now, then they're just squeezing," Dershowitz told CNN. "It doesn't sound like they have very much new here."
One of the reasons Kadyrbayev drew investigators' attention was because of changes to his Facebook page, a source briefed on the Boston probe said. Kadyrbayev and Dzhokhar Tsarnaev changed their profile photos within 15 minutes of each other in the pre-dawn hours of April 19, while the Tsarnaevs were on the run, the source said.
Tsarnaev, who appears to have had access to a wireless device at that time, changed his to a black-and-white photo, while Kadyrbayev changed his photo to one of him wearing an Iron Man mask, the source said.