WASHINGTON — Attorney General Eric Holder, rejecting concern about security risks, announced Friday that confessed 9/11 mastermind Khalid Sheikh Mohammed and four alleged underlings will face a federal court trial in New York just blocks from the scene of the worst terrorist attack in U.S. history.

Holder said he had elected to forgo military trials and proceed with the first U.S. criminal prosecution of figures alleged to have been directly involved in the suicide hijacking plot eight years ago because of his complete confidence in a "successful outcome." He said he expected to ask for the death penalty.

The decision to attempt criminal prosecutions of the 9/11 figures set off intense debate from both ends of the political spectrum over whether the trial will make New York a magnet for terrorism, risk the release of some of the world's most dangerous terrorists because of issues such as brutal interrogation techniques used on them in secret prisons or be unfair because some or all of the defendants are mentally incompetent after years of isolation.

Human rights groups hailed the decision, which administration officials described as a "significant step" toward fulfilling President Barack Obama's campaign promise to close the detention center at the U.S. naval base in Guantanamo Bay, Cuba.

Holder also said that he had decided that five other Guantanamo detainees will stand trial before military commissions, including Abd al-Rahim al-Nashiri, who is accused of orchestrating the October 2007 attack on the Cole that killed 17 U.S. sailors and injured 39 others.

He said that a grand jury indictment soon would be returned against:

Mohammed — who has admitted to spearheading the planning but whom U.S. interrogators subjected to simulated drowning techniques at a secret overseas prison after his capture in March 2003.

Ramzi Binalshibh — who was turned away at the U.S. border four times before the attacks, even offering to marry a U.S. citizen to gain access, before allegedly acting as the prime coordinator for the 19 hijackers from Germany.

Waleed bin Attash — who the U.S. government says was intended to be a hijacker until he was captured in Yemen earlier in 2001.

Mustafa Ahmed al-Hawsawi — the alleged paymaster, suspected of managing the funding for the hijackings and wiring money to the hijackers.

Ali Abd al-Aziz Ali — a Pakistan-based operative who allegedly transferred money to the U.S. operatives and facilitated their travel from Pakistan to the United States.

All five have been held for years at Guantanamo Bay.