Omar Khadr, right, pleads guilty under oath Monday to all five terrorism charges against him before Col. Patrick Parrish, the military commission judge hearing the case in Guantanamo Bay, Cuba. (Janet Hamlin/Reuters)

Omar Khadr threw a grenade with the intent of killing as many Americans as he could and told interrogators he felt happy that he had killed a U.S. soldier, according to a statement of facts agreed to by Khadr himself.

According to the document, which was read aloud during his sentencing hearing Tuesday at the U.S. naval base in Guantanamo Bay, Cuba, Khadr threw the grenade after a firefight with U.S. soldiers had ended and knowing the Americans were looking for the wounded or dead.

He did so "with the specific intent of killing or injuring as many Americans as he could," according to the document, which was read aloud by U.S. prosecutor Jeff Groharing.

The nine-page document describes in detail the 24-year-old Khadr's life, his connections to al-Qaeda and actions leading up to and following his murder of Sgt. Christopher Speer in July 2002. Khadr appears to have signed the document — attesting to its accuracy — on Oct. 13, 2010.

Among other things, it also says the Toronto-born Khadr:

• Knew his father had a close relationship with the head of al-Qaeda, Osama bin Laden.
• Attended one-on-one private terrorist training from a member of al-Qaeda.
• Learned to use rocket-propelled grenades, assault rifles and improvised explosive devices during training in Afghanistan in June 2002.
• Hoped to kill "a lot of Americans" in order to receive reward money ($1,500 US per American killed.)
• Chose to engage in a firefight with U.S. troops while armed with an AK-47 Kalashnikov rifle and pistol.
• Has no legal defence to any of the charges to which he pleaded guilty.

These and other details formed the basis of a deal in which Khadr pleaded guilty Monday to five war crimes, including murder and conspiracy.

Jury urged to keep open mind

The military judge in the case, Col. Patrick Parrish, began Tuesday's hearing by asking the seven jurors, who will recommend Khadr's sentence, if they had read or heard about the case in the news media.

Parrish then urged the jurors — all U.S. military officers — to "keep an open mind," reminding them of their "grave responsibility … to exercise with wide discretion."

Khadr will serve no more than eight years in prison, his Canadian lawyer, Dennis Edney, said Monday. The 24-year-old will have to serve a maximum of one year of his sentence at Guantanamo Bay before he may apply to serve the remainder in Canada, Edney said.

The sentence is part of a plea deal reportedly agreed to by the Canadian government, he said. In a phone interview with the CBC from Guantanamo Bay, Edney labelled the plea deal "a piece of paper," and said his client "would have confessed to anything, including the killing of John F. Kennedy, just to get out of this hellhole."

"Had Omar refused, then he was faced with an unfair trial based on evidence that would be inadmissible in a real court and the potential of life in prison in Guantanamo Bay."

Diplomatic notes exchanged between Canada and the U.S. suggest the American government also agreed to the plea deal.

Parrish has said he will release the notes by week's end.

Convicted war criminal

Khadr, who was born in Toronto, has been held at Guantanamo Bay since 2002, after he threw a grenade during a battle with American forces in Afghanistan, killing Sgt. Christopher Speer.

Khadr had vehemently denied U.S. allegations that he was responsible for Speer's death.

But on Monday morning, Khadr withdrew his previous pleas of not guilty to five war crimes charges, including murder in violation of the laws of war, attempted murder in violation of the laws of war, conspiracy, providing material support to terrorists and spying.

He told the court no one had forced him to change his pleas. When asked if he had killed Speer in 2002, Khadr answered, quietly, "Yes." When asked if it was true that he conspired with Osama bin Laden and al-Qaeda, he also answered "Yes."

Tuesday's sentencing hearing could last several days.

Speer's widow, Tabitha Speer, is slated to address the court, the first time she will have a chance to tell Khadr directly about the impact his crimes have had on her.

Prosecutors and defence lawyers will call a total of 14 witnesses, including psychiatrists.

Details of the plea deal are also expected to be made public.

During Tuesday's question period in the House of Commons, Liberal foreign affairs critic Bob Rae called on the government to state clearly what the Canadian government's policy is on the Khadr file.

Rae said the Conservatives were "playing a game of let's pretend" over Khadr's plea agreement and the government's diplomatic role in it, as well as the fact he was a child soldier when he was captured by U.S. forces.

Foreign Affairs Minister Lawrence Cannon replied the trial is underway and "concerns Mr. Khadr, his lawyers and the U.S. justice system."

With files from the CBC's Derek Stoffel and The Canadian Press