Factbox: Reaction to Guantanamo trial for Sept. 11 suspects

(Reuters) - Attorney General Eric Holder on Monday said self-professed September 11 mastermind Khalid Sheikh Mohammed and four co-conspirators will be tried in a military commission at Guantanamo Bay, and not in a New York criminal court as U.S. President Barack Obama had hoped.

Civil liberties advocates had hailed the initial plan to try the men in New York, but many people in New York sharply opposed the trials.

Here are some comments:

NEW YORK CITY MAYOR MICHAEL BLOOMBERG:

"Kindly recall the cost for security operations to New York for hosting the trial would have been a billion dollars.

"It's probably more appropriate to do it in a secure area with a military tribunal, and what I've read about military tribunals is they're not an automatic kind of thing. They are a different form of a legal system, but something that this country can implement and not be ashamed of it."

NEW YORK CITY POLICE COMMISSIONER RAYMOND KELLY:

"It's a common sense decision. We support it.

"We were prepared to handle it (but) it would have cost a lot of money."

ANDREA PRASOW, SENIOR COUNTERTERRORISM COUNSEL AT HUMAN

RIGHTS WATCH:

"Any trial in the military commission system will carry the stigma of Guantanamo, be subject to challenge and delay, and keep the world focused on how the defendants were treated rather than the crimes they are accused of committing.

"A verdict in the federal court system, in contrast, would be recognized throughout the world as legitimate."

VALERIE LUCZNIKOWSKA, WHO LOST HER NEPHEW ON SEPT. 11

"We have a perfectly good federal court system, it has worked for a couple hundred -- at least-- terrorism cases. It's just not satisfying (the Holder decision) to people who want real justice."

COMMUNITY BOARD 1 CHAIR JULIE MENIN:

"We are extremely relieved to hear that the administration has decided not to hold the trials in Lower Manhattan, where they would have had a severe and long-term impact on the safety and quality of life of residents and workers."

U.S. SENATOR CHARLES SCHUMER, A DEMOCRAT FROM NEW YORK:

"While not unexpected, this is the final nail in the coffin of that wrong-headed idea.

"I have always said that the perpetrators of this horrible crime should get the ultimate penalty, and I believe this proposal by the administration can make that happen."

U.S. SENATORS JOHN MCCAIN AND JOE LIEBERMAN

"KSM and the other alleged co-conspirators are charged with war crimes and their cases belong before military commissions, not federal courts here in the United States."

"Congress, working with the Obama Administration, made significant improvements to military commissions in 2009 and provided a means to try terrorists who have violated the law of war with a criminal process that is fair and consistent with our values while ensuring the safety of American citizens and preserving classified information during wartime."

MIKE ROGERS, CHAIRMAN OF THE HOUSE PERMANENT SELECT

COMMITTEE ON INTELLIGENCE:

"The president and the Attorney General deserve credit for their willingness to acknowledge that serious shortcomings have existed all along in their plans to force dangerous international terrorists into the civilian justice system.

"Those flawed plans could have endangered intelligence sources and collection efforts and also risked the safety of Americans in New York."

PETER T. KING, CHAIRMAN OF THE COMMITTEE ON HOMELAND

SECURITY:

"Today's decision ... is a long-awaited step in the right direction.

"As I have been saying since day one, these terror trials belong in a military commission at Guantanamo. I am absolutely shocked that it took Attorney General Holder 507 days to come to this realization."

(Reporting by Basil Katz in New York and the Washington newsroom; Editing by Daniel Trotta and Todd Eastham)