Terror, murder charges could be filed against Boston suspect NEW: Federal terrorism charges could be filed soon, Justice Department official says Russian President Vladimir Putin wants to get details from U.S. on bombing suspects If physically able, suspect could be in court this weekend, expert says Two U.S. senators say Dzhokar Tsarnaev should be questioned without a lawyer (CNN) -- Federal terrorism charges against Boston Marathon bombings suspect Dzhokar Tsarnaev could be filed soon, even as he remains hospitalized, a Justice Department official told CNN on Saturday. The 19-year-old could also face murder charges at the state level. Federal prosecutors are at the heavily guarded Beth Israel Deaconess Medical Center, where Tsarnaev remains in serious condition while in federal custody, and they are working on formulating the charges. This development comes amid questions as to what's next for the suspect in the Boston Marathon bombing. "There are still many unanswered questions," Obama said Friday night. Tsarnaev and his older brother, Tamerlan Tsarnaev, are accused of setting off bombs at the marathon Monday, killing three people and leaving more than 170 wounded. On Thursday night, they allegedly killed a Massachusetts Institute of Technology police officer before the older brother was killed in a shootout with police. Dzhokar Tsarnaev was captured alive Friday night after he was found hiding in a boat in a Watertown, Massachusetts, backyard. When will the suspect be in court? "In normal circumstances, someone arrested on Friday night would not be arraigned until Monday morning, but because of the extraordinary circumstance here he may be arraigned on (Saturday)," said CNN senior legal analyst Jeffrey Toobin. Ordinarily at an arraignment, the suspect is provided a lawyer, and the defense and prosecution try to make a case to release him on bail. For now, the government is invoking the public safety exception, a designation that allows investigators to question Tsarnaev without reading him his Miranda rights, a Justice Department official told CNN on condition of anonymity. But this is not an ordinary case, say U.S. Sens. John McCain and Lindsey Graham. They urged that Tsarnaev be held as an "enemy combatant," a designation that allows a suspect to be questioned without a lawyer and without being informed of his Miranda rights. Under the law of war we can hold this suspect as a potential enemy combatant not entitled to Miranda warnings or the appointment of counsel. Alan Dershowitz, a prominent defense attorney and Harvard law professor, scoffed at the senators' statement. There's no way an American citizen committing a domestic crime in the city of Boston could be tried as an enemy combatant," he told CNN's Piers Morgan. Dershowitz also said statements made by police in Boston seems to contradict the government's reasons for invoking the public safety exception. "The police have said there's no public safety issue; it's solved, it's over," Dershowitz said. There are no further threats. But the FBI is saying there's enough further threats to justify an exception. Former New York Mayor Rudy Giuliani said the federal government may have known about international threats about which state officials were not aware. "You would have to know the internals of what they have before you can assess whether there is a sensible invocation or not," Giuliani said. If the government had prior knowledge of Tsarnaev's activities, it hasn't disclosed it. It did say that Tamerlan Tsarnaev was on the FBI's radar in the past. FBI agents interviewed Tamerlan two years ago and also looked at his travel history, checked databases for derogatory information and searched for Web postings. The agency found no connection with terror groups, an FBI official told CNN. Tamerlan Tsarnaev, who was not a U.S. citizen, traveled to Sheremetyevo, Russia, in January 2012, according to travel records provided by a U.S. official. He returned six months later. "If he says my intent was to please my brother, they could raise the question of federal jurisdiction," Dershowitz said. This fight over federal or state jurisdiction could mean life or death. There's another big question: The National Defense Authorization Act of 2012 requires mandatory temporary military custody of certain terror suspects, but Dzhokar Tsarnaev is a U.S. citizen, and the act doesn't apply to Americans. U.S. Attorney Carmen Ortiz said Friday her office is ready to get started on the case. "My journey and my office's journey begins," Ortiz said. And this investigation continues. And as the days continue you will get answers. What is the reaction in the suspects' homeland? Tsarnaev's family lives in the Russian republic of Dagestan, which is next to the suspects' homeland of Chechnya, located in the North Caucasus region of southern Russia. Russia's investigative committee in Dagestan said it will not engage with the Tsarnaev family unless there is "an order from above" to do so, spokesman Rasul Temerbekov told Russian state news agency RIA Novosti on Saturday. A spokesman for Russian President Vladimir Putin said Saturday that Russia wants to get official information from the United States about the bombing suspects, and he wants there to be contact between investigators in both countries.