A team of investigators from the U.S. Embassy in Moscow questioned both parents in Russia this week.
Late this week, Dzhohkar Tsarnaev was taken from Beth Israel Deaconess Medical Center, where he was recovering from a throat wound and other injuries suffered during an attempt to elude police, and was transferred to the Federal Medical Center Devens, about 40 miles from Boston, the U.S. Marshals Service said. The facility, at a former Army base, treats federal prisoners.
"It's where he should be; he doesn't need to be here anymore," said Beth Israel patient Linda Zamansky, who thought his absence could reduce stress on bombing victims who have been recovering at the hospital under tight security.
Two college buddies of his — Azamat Tazhayakov and Dias Kadyrbayev — have been interviewed at length, twice, by FBI agents and have cooperated fully, said Kadyrbayev's lawyer, Robert Stahl, a former federal prosecutor.
They were detained April 20 after being questioned in connection with the attacks, but are not suspects, Stahl said. They are being detained at a county jail in Boston for violating their student visas by not regularly attending classes, he said.
The two, both students from Kazakhstan, had nothing to do with the attack and had seen no hints that their friend harbored any violent or terrorist sympathies, Stahl said.
Meanwhile, New York's police commissioner said the FBI was too slow to inform the city that the Boston Marathon suspects had been planning to bomb Times Square days after the attack at the race.
Federal investigators learned about the short-lived scheme from a hospitalized Dzhokhar Tsarnaev during a bedside interrogation that began Sunday night and extended into Monday morning, officials said. The information didn't reach the New York Police Department until Wednesday night.
"We did express our concerns over the lag," said police Commissioner Raymond Kelly.
The FBI had no comment Friday.
Sullivan reported from Washington. Contributing to this report were Associated Press writers Rodrique Ngowi in Boston, Colleen Long in New York and Ted Bridis, Pete Yost and Julie Pace in Washington.