Public defenders raise concerns about upcoming interrogation of bombing suspect As the lone surviving suspect in the Boston Marathon bombing lay hospitalized under heavy guard, Boston Mayor Tom Menino said authorities may never be able to question him. Dzhokhar Tsarnaev, 19, was in "very serious" condition at a Boston hospital after being captured Friday night, Menino told ABC. "And we don't know if we'll ever be able to question the individual," he said without elaborating. The American Civil Liberties Union and a federal public defender have been raising concerns about investigators" plans to question him without reading him his rights. What Tsarnaev might say and when are unclear. He was pulled bloody and wounded Friday evening from a tarp-covered boat in a Watertown backyard. The capture came at the end of a tense Friday that began with his 26-year-old brother, Tamerlan, dying in a gun battle with police. Tsarnaev might be charged as early as Sunday, CNN reported, but there was not word on what those charges would be. The twin bombings killed three people and wounded more than 180. The most serious charge available to federal prosecutors would be the use of a weapon of mass destruction to kill people, which carries a possible death sentence. Massachusetts does not have the death penalty. U.S. officials said an elite interrogation team would question the Massachusetts college student without reading him his Miranda rights, which guarantees the right to remain silent and the right to an attorney. Such an exception is allowed on a limited basis when the public may be in immediate danger, such as instances in which bombs are planted and ready to go off. ACLU Executive Director Anthony Romero said the legal exception applies only when there is a continued threat to public safety and is "not an open-ended exception" to the Miranda rule. The federal public defender's office in Massachusetts said it has agreed to represent Tsarnaev once he is charged. Miriam Conrad, public defender for Massachusetts, said he should have a lawyer appointed as soon as possible because there are "serious issues regarding possible interrogation." President Barack Obama said there are many unanswered questions about the bombing, including whether the Tsarnaev brothers - ethnic Chechens from southern Russia who had been in the U.S. for about a decade and lived in the Boston area - had help from others. The President urged people not to rush judgment about their motivations. Investigators have not offered a motive for the Boston attack. But in interviews with officials and those who knew the Tsarnaevs, a picture has emerged of the older one as someone embittered toward the U.S., increasingly vehement in his Muslim faith and influential over his younger brother. The Russian FSB intelligence service told the FBI in 2011 about information that Tamerlan Tsarnaev was a follower of radical Islam, two law enforcement officials said Saturday. According to an FBI news release, a foreign government said that Tamerlan Tsarnaev appeared to be a strong believer and that he had changed drastically since 2010 as he prepared to leave the U.S. for travel to a region in Russia to join unspecified underground groups. The FBI did not name the foreign government, but the two officials said it was Russia. The officials spoke on condition of anonymity because they were not authorized to talk about the matter publicly. The FBI said that in response, its agents interviewed Tamerlan Tsarnaev and relatives, and did not find any domestic or foreign terrorism activity. The bureau said it looked into such things as his telephone and online activity, his travels and his associations with others. An uncle of the Tsarnaev brothers said he had a falling-out with Tamerlan over the man's increased commitment to Islam. Ruslan Tsarni from Maryland said Tamerlan told him in a 2009 phone conversation that he had chosen "God's business" over work or school. Tsarni said he then contacted a family friend who told him Tsarnaev had been influenced by a recent convert to Islam. Tsarni said his relationship with his nephew basically ended after that call. As for Dzhokhar Tsarnaev, "he's been absolutely wasted by his older brother. I mean, he used him. He used him for whatever he's done," Tsarni said. Albrecht Ammon, a downstairs-apartment neighbour of Tamerlan Tsarnaev in Cambridge, said in an interview that the older brother had strong political views about the United States. Ammon quoted Tsarnaev as saying that the U.S. uses the Bible as "an excuse for invading other countries." Tamerlan Tsarnaev studied accounting as a part-time student at Bunker Hill Community College in Boston for three semesters from 2006 to 2008, the school said. He was married with a young daughter. Dzhokhar Tsarnaev was a student at the University of Massachusetts Dartmouth. As of Saturday, more than 50 victims of the bombing remained hospitalized, three in critical condition.