Updated

The Obama administration's decision to try self-proclaimed Sept. 11 mastermind Khalid Sheikh Mohammed and his alleged co-conspirators in the city that suffered the worst attack on U.S. soil presents monumental legal challenges and risks to U.S. national security, legal experts say, not least of which include establishing a trail of evidence and ensuring public safety in New York.

Attorney General Eric Holder announced Friday that Mohammed and four other Guantanamo detainees will be tried in federal court in New York for their alleged role in the attacks that killed 2,976 American civilians -- saying the U.S. will seek the death penalty against the defendants.

"After eight years of delay, those allegedly responsible for that attacks of September the 11th will finally face justice," Holder said. "They will be brought to New York -- to New York -- to answer for their alleged crimes in a courthouse just blocks away from where the twin towers once stood."

But the decision to send the Mohammed and his accomplices to New York rather than trying them before a military tribunal has been met with strong resistance. Attorneys prosecuting Mohammed will be forced to release a large body of classified U.S. intelligence information that critics say will give fodder to potential terrorist attacks -- both domestically and abroad.

Former federal prosecutor Andrew McCarthy, who led the prosecution in the case against Sheik Omar Abdel Rahman for his role in the 1993 World Trade Center bombings, said public trials will provide a "banquet of intelligence information" for the vast Al Qaeda network, especially operatives in Afghanistan.

"It's a massively stupid decision when we're actually at war with them," McCarthy said in an interview with FoxNews.com. "We have to give them all kinds of information about our methods of intelligence that can only make them more efficient at killing us."

Otto Obermaier, on the other hand, called the Obama's administration's move "a wise decision" legally. Obermaier was appointed by President George H. W. Bush to serve as a U.S. attorney for the Southern District of New York from 1989 to 1993 and is a partner at Martin & Obermaier, LLC.

"You couldn't have chosen better than Southern New York. ... It's the most the talented United States attorneys office in the country -- indeed I say the world."

Others, like Republican Sen. Jon Kyl of Arizona, said bringing Mohammed to New York was "an unnecessary risk" that would result in the disclosure of confidential information on U.S. intelligence tactics. Kyl maintained the trial of Rahman, the so-called "blind sheik," caused "valuable information about U.S. intelligence sources and methods" to be revealed to the Al Qaeda terrorist network.

Supporters of the move say they would rather see Mohammed face a New York jury than sit before a military tribunal because the attacks on Sept. 11 -- despite being aimed in part at the Pentagon -- were not "military infractions."

Democratic Sen. Kirsten Gillibrand of New York said Friday the U.S. must "avoid political wrangling and remain focused on seeking justice for the families who lost loved ones due to these terrorists' heinous acts." New York City Mayor Michael Bloomberg also supported the decision, saying it is "fitting that 9/11 suspects face justice near the World Trade Center site where so many New Yorkers were murdered."

Alberto Gonzales, attorney general under President George W. Bush, told FoxNews.com Friday that he has concerns over the move, but stopped short of taking a position on the decision. Gonzales said his Justice Department always believed the president had the option of either trying someone in a military tribunal or in a U.S. federal court, depending on the circumstances.

"I don't know whether there's additional information or evidence that may be available to prosecutors that wasn't available when I was attorney general," Gonzales said.

Michael Mukasey, Holder's predecessor under the Bush administration, said the decision was not only unwise but based on what he called a refusal to acknowledge that the U.S. it at war -- and that the crimes perpetrated on Sept. 11 constitute war crimes.

Critics also point to the difficulty in selecting an impartial jury and to the grave security concerns that come from holding Mohammed and his accomplices in a New York City prison.

"How do you have a trial on 9/11 terrorists in New York with people who don't have some sort of opinion on this?" said Annemarie McAvoy, a New York-based attorney and former federal prosecutor.

McCarthy cited a violent attack by Mamdouh Salim, a former Al Qaeda operative who was being held in 1998 at the Metropolitan Correction Center in New York -- the prison facility likely to house the five alleged Sept. 11 plotters. Salim blinded a prison guard and stabbed him with a sharpened comb, causing extensive brain damage in what federal officials say was an attempt to take hostages and escape. Salim had been extradited to the United States from Germany for his role in the 1998 U.S. Embassy bombings in Tanzania and Kenya.

"I'm assuming the prosecution has evaluated the risk and has determined they can achieve a successful conviction here without compromising the national security of our country," said Gonzales.

The New York case may also force the court system to confront a host of difficult legal issues surrounding counterterrorism programs begun after the 2001 attacks, including the harsh interrogation techniques once used on some of the suspects while in CIA custody.

The most severe method -- waterboarding, or simulated drowning -- was used on Mohammed 183 times in 2003, before the practice was banned.

"Clearly, it does provide a platform -- an opportunity -- for the defense to talk about certain actions taken by the government to protect our country," Gonzales said, but "I can't get into the hearts and minds of the decision makers. I know that the prosecutors involved at the Department of Justice are all going to be focused on one thing -- to win this case."

Victims' family members like Wright Salisbury, whose son-in-law Edwards Hennessy Jr. of Belmont, Mass., died aboard American Flight 11, also backed the move.

"I don't care if it's a victory for them. Khalid Sheikh Mohammed has said he wanted to be executed, and I think the best thing we could do is not execute him, but I can't say how the jury is going to decide," said Salisbury, who is a member of the group 9/11 Families for Peaceful Tomorrows, an anti-war organization formed by relatives of Sept. 11 victims.

The Associated Press contributed to this report.