The friends were identified in a federal complaint as Dias Kadyrbayev and Azamat Tazhayakov, both 19-year-olds from Kazakhstan who were in the United States on student visas, and Robel Phillipos, 19, of Cambridge, Mass. All are current or former students at U-Mass.-Dartmouth.
The two Kazakhs were accused of removing a laptop computer and a backpack containing empty fireworks from Tsarnaev’s dorm room and throwing them in a dumpster after learning of his suspected involvement in the bombing. Phillipos was charged with lying to federal investigators.
All three men appeared in federal court in Boston on Wednesday and agreed to voluntary detention. The next hearing is set for May 14. Attorneys for the three said outside the courthouse that their clients had nothing to do with the bombing and had cooperated fully with the investigation.
The three were not accused of involvement in the attack, but a footnote in court papers said that about a month before the bombing, Dzhokhar Tsarnaev told Tazhayakov and Kadyrbayev that he knew how to make a bomb.
The charges were accompanied by an affidavit by FBI agent Scott P. Cieplik that provided new details of Tsarnaev’s actions after the bombing and laid out how his friends, after recognizing him on TV as one of the suspects, allegedly tried to help him.
The bombing on April 15 killed three people and injured more than 260. About 5 p.m. April 18, law enforcement authorities released video and photographs from cameras near the scene that showed two suspects.
Kadyrbayev told the FBI that a few minutes later he received a telephone call from Phillipos, who told him to turn on the television because one of the suspects looked familiar. Kadyrbayev said that one of the suspects looked like Tsarnaev and that he texted Tsarnaev, saying he looked like the man on television.
Kadyrbayev and Tazhayakov, who share an apartment, had met Tsarnaev in foreign-student circles at the university. Tazhayakov’s attorney, Linda Cristillo, said in a statement that they were acquaintances, but the FBI affidavit described the two men as close friends of Tsarnaev’s who talked to him in the two days after the bombing.
Tazhayakov said Tsarnaev gave him a ride home from campus on April 16. Kadyrbayev told the FBI he met Tsarnaev outside his dorm on April 17 and noticed he had given himself a short haircut.
Shortly after being alerted to Tsarnaev’s resemblance to one of the suspects on April 18, Kadyrbayev, Tazhayakov and Phillipos went to Tsarnaev’s dorm room. Just before entering, Kadyrbayev showed Tazhayakov a text message from Tsarnaev — “I’m about to leave if you need something in my room take it.” Tazhayakov told the FBI he believed he would never see Tsarnaev alive again.