Bringing charges in federal court would end a brewing debate in Washington over how to handle the case. Four Republican members of Congress — Sens. John McCain (Ariz.), Lindsey O. Graham (S.C.), Kelly Ayotte (N.H.) and Rep. Peter T. King (R-N.Y.) — had demanded Saturday that Tsarnaev be treated as an “enemy combatant” rather than as a common criminal suspect. That would enable the government to charge him under the laws of war in a military commission or to hold him indefinitely without charges.
But prominent Democrats disagreed Sunday, saying that Tsarnaev should not be treated as an enemy combatant and that he should be prosecuted in federal court. “I do not believe under the military commission law that he is eligible for that. It would be unconstitutional to do that,” said Sen. Dianne Feinstein (D-Calif.), chairman of the Senate Intelligence Committee, during an appearance on “Fox News Sunday.”
Even as the case’s disposition remained unclear, the massive investigation into the bombing continued. Federal law enforcement officials said they are trying to learn everything they can about Tamerlan Tsarnaev’s six months abroad last year — all the places he went and with whom he met. They are also trying to determine how he learned to make bombs and where he might have practiced exploding them.
Also under investigation, law enforcement officials said, is whether Tamerlan traveled abroad under a different name.
The Bureau of Alcohol, Tobacco, Firearms and Explosives, which has hundreds of agents working to collect and investigate the explosives used in the bombing, is trying to trace the guns the suspects had — at least one handgun and possibly several more. Cambridge Police Commissioner Robert Haas told the Associated Press on Sunday that neither brother had gun permits allowing them to legally carry firearms. Haas said it was unclear whether either brother applied for a permit.
So far, the bombing has not been linked to any overseas terrorist network or any larger terrorist cell within the United States. On Sunday, Islamist separatist groups in Dagestan denied any connection to the attack, saying that their enemy was Russia and not the United States.
“We are at war with Russia, which is not only responsible for the occupation of the Caucasus, but also for heinous crimes against Muslims,” said a statement posted on the Web site for the Mujahideen of the Caucasus Emirate Province of Dagestan.
Also unclear Sunday was whether the brothers had planned to launch other attacks.
Boston Police Commissioner Ed Davis said the brothers’ arsenal of weapons and unexploded bombs suggested that they were preparing for other operations. “I personally believe they were,” Davis said on CBS’s “Face the Nation.”
But Menino downplayed that possibility in an interview on ABC’s “This Week,” saying, “I’m not convinced that they were planning more attacks,” he said.
Wiktor P. Tomkiewicz, 20, said he met Tsarnaev for the first time on April 11, with a group of friends for lunch. Over pizza and calzones, six students talked about school.
“He seemed like someone I would hang out with,’’ said Tomkiewicz, a junior civil engineering major. Then he saw the photos and thought: “It’s freaky. I just had lunch with him.”
Kathy Lally and Will Englund in Moscow, Greg Jaffe, Julie Tate and Joel Achenbach contributed to this report.