Civil liberties advocates have said a suspect should rarely be questioned without a lawyer and without being told he doesn't have to respond.
"Miranda rights are an incredibly important civil liberties safeguard," said Hina Shamsi of the American Civil Liberties Union. "The public safety exception must be read narrowly, as it has been by the courts."
But California Democratic Rep. Adam Schiff, a former federal prosecutor, said he has questions about how the court proceeding came about.
"I would have thought the public safety exception would have allowed more time for the questioning of the suspect prior to the arraignment and/or advising of rights," Schiff said.
Based on the younger man's interrogation and other evidence, authorities have said it appears so far that the brothers were radicalized via Islamic jihadi material on the Internet instead of any direct contact with terrorist organizations, but they warned it is still not certain.
The brothers are ethnic Chechens from Russia who came to the United States about a decade ago with their parents. The family was granted asylum.
The chairman of the House Judiciary Committee said Thursday that the way the U.S. grants asylum to immigrants may need to be addressed after the marathon bombings.
"People getting asylum because they are in the minority, but engaging in aggressive tactics in their home country that may cause them to be susceptible to doing the same thing elsewhere, that obviously ought to be a part of our consideration in granting political asylum to avoid situations like Boston," said Rep. Bob Goodlatte, R-Va., who's working to develop a series of bills to fix problems with the country's immigration system.
Homeland Security Secretary Janet Napolitano defended the asylum process this week in an appearance before the Senate Judiciary Committee, saying it involves multiple layers of vetting.