The self-proclaimed mastermind of the September 11th terrorist attacks will be tried in the city, United States Attorney General Eric Holder announced Friday.

Khalid Sheikh Mohammed, above, is one of five alleged September 11th terrorists who will be sent to New York from Guantanamo Bay to face trial by jury in a civilian federal court.

Mohammed and the other detainees will be tried in a courthouse just blocks away from the World Trade Center site.

The attorney general said he spoke with Mayor Michael Bloomberg and Governor David Paterson about the decision and all security concerns will be addressed.

Police Commissioner Ray Kelly said the New York City Police Department is prepared to handle the arrival and added that he feels the decision to move the trial to the city is completely appropriate.

"In my judgment, they are responsible for the deaths of 3,000 people right here in Manhattan," Kelly said. "And I think they should be tried in the venue where they committed the crime. That's always been our standard in the criminal justice system in this country. So I see it as fitting and appropriate."

Holder said he will seek the death penalty in all of the trials and that he believes family members of the victims deserve to see the alleged terrorists face justice.

"These were extraordinary crimes and so we will see maximum penalties," he said. "Federal rules allow us to seek the death penalty for capital offenses. While we will review the evidence and circumstances following established protocol, I fully expect to direct prosecutors to seek the death penalty against each of the alleged 9/11 conspirators."

While the September 11th terror suspects will not go before military commissions, the suspects in the USS Cole bombing in 2000 who are also detained at Guantanamo Bay will have military trials.

"It's a victory for the rule of law because these people have been in custody, they're suspected of committing serious crimes, they should be brought to justice, tried according to law, sentenced according to law," said former federal prosecutor Alan Vinegard. "And that's what the attorney general's decision today is going to bring about."

Many relatives told NY1 that they are concerned with the decision.

"I don't think it's a bad thing for New Yorkers or America to remember what happened," said Frank Siller, whose brother, a firefighter, died on September 11th. "But I think it's a bad thing to take it out of where it is, in Gitmo, they should be tried by a military court and whatever the outcome is, and they should be sentenced accordingly. They're not Americans; they don't deserve the same rights as Americans. They killed 3,000 people that day and they're trying to kill us still today."

Not everyone is opposed.

"The family of the victims would probably attend the trials, and I think it would be some closure for them," said a New Yorker.

"They attacked us here, this is the epicenter of the United States, somewhat, they should have a trial and face justice here," agreed another.

Bloomberg supports Holder's decision, and said in a statement, "New York City stands ready to assist the federal court in the administration of justice in any way necessary. I have great confidence that the NYPD, with federal authorities, will handle security expertly."

Former Mayor Rudy Giuliani, however, disagreed with bringing some of the Guantanamo Bay detainees to the city.

"This is the same mistake we made with the 1993 terrorists who attacked the World Trade Center," said Giuliani. "We treated them like domestic criminals, when in fact they were terrorists. In the dangerous world we live in today, a nation unable to identify and properly define its enemies is a nation in danger."

The move comes ahead of a Monday deadline for the government to decide how to proceed against 10 detainees facing military commissions. It's also seen as a key step in President Barack Obama's plan to close the detention center at Guantanamo Bay.

It will take at least 45 days to transfer the five defendants to New York due to legal and security issues.

Josh Dratel, a defense attorney who has worked on terrorism cases before, said he doubts the trial itself will happen anytime soon.

"We're looking at a trial probably not in 2010. I'm not sure if we're looking at a trial in 2011," said Dratel.

Holder said Friday he is confident that the transfer will happen as quickly as possible.