GUANTANAMO BAY, Cuba - Omar Khadr is an angry, bitter and remorseless jihadist with strong ties to his "al-Qaida family," a prosecution psychiatrist told a sentencing hearing Tuesday for the newly convicted Canadian-born war criminal.

Khadr's mother, brothers and sister, who live in Toronto, have all expressed support for violent jihad, Dr. Michael Welner told court, as he described Khadr as the "white sheep" of the family.

During eight years in custody at the U.S. military's infamous Guantanamo Bay prison, Khadr has "marinated in radical jihadism" among his fellow prisoners and only grown more devout, Welner said during testimony one observer described as "ideological."

"He's highly dangerous," Welner said. "It is his belief that he should not have been here for a day . . . and that it is everybody else's fault that he is."

The jurors also heard that the "charming" and "very gracious" Khadr is considered a religious leader by other inmates at Camp 4, where he is housed.

"He murdered," Welner said. "He murdered an American soldier, which is the ultimate prize in Camp 4."

The damning testimony capped a day in which court heard how, in the midst of a deadly firefight in Afghanistan in 2002, a 15-year-old Khadr — convinced he was about to die — decided to try to kill as many Americans as he could.

The seven U.S. military officers listened intently as U.S. prosecutor Jeff Groharing read into the record the 50-paragraph agreed statement of facts that form the underpinning of Khadr's guilty plea the day before.

The statement described how Khadr, with U.S. soldiers on his doorstep, tossed a Russian-made F1 grenade from behind a wall, dealing a mortal head wound to Sgt. 1st Class Christopher Speer, who succumbed to his injuries 12 days later.

"Khadr threw the grenade with the specific intent of killing or injuring as many Americans as he could," Groharing read.

The Toronto-born Khadr, now 24, was holed up with other members of a terrorist cell in a compound that was coming under American attack. They made a "pact" that they would sooner die than surrender to their western enemies.

He was shot twice by an American special forces soldier, and found badly wounded in the rubble of the compound, which had been hit by two 500-pound bombs. He was also blinded in one eye by shrapnel during the attack.

Khadr — who pleaded guilty Monday to five war-crimes charges, including Speer's murder — admitted to being "happy" at the news that he had killed an American soldier, and would take comfort in it while in custody at Bagram Air Base outside Kabul.

"Khadr indicated that when he would get 'pissed off' with the guards at Bagram, he would recall his killing of the U.S. soldier and it would make him feel good."

Khadr also admitted to receiving terrorist training throughout his late childhood and early teens during travels with his father, an associate of Osama bin Laden, in Afghanistan and Pakistan.

"Khadr considered himself to be an active member of al-Qaida and he shared the same goals as the organization, which are to target and kill all Americans — whether civilian or military — anywhere they can be found, and to 'plunder their money,'" the statement read.

Khadr signed the document, which essentially concedes all the American allegations against him, on Oct. 13.

In accordance with military commission rules, the jury will decide what sentence Khadr deserves, although he won't serve more time than the eight years set out in a plea-bargain agreement. The panel has not been told about the cap.

Part of that deal is that Khadr would be allowed to apply for a transfer to a Canadian facility after one more year in U.S. custody, something Welner said was problematic.

"There is no de-radicalization program in Canada," he said.

Khadr has taken no steps to further his secular education, and has not embraced western culture, even though he reads "Harry Potter" as a distraction, the New York-based psychiatrist said.

Alex Neve, head of Amnesty International Canada, denounced Welner's opinions, particularly the spin the psychiatrist put on Khadr's religious devotion.

"I've rarely heard anything so over the top and outrageous," Neve said. "Clearly, this is a psychiatrist who has some very strong ideological views."

In the statement of facts, Khadr admitted to being a terrorist and an "unprivileged" enemy combatant — a murky term used to describe a civilian who is not considered a legitimate enemy soldier, and therefore deemed ineligible for certain rights and protections.

That designation, which has been hotly contested as illegitimate by legal experts and human-rights advocates alike, is why Khadr was charged with war crimes, rather than criminal offences.

The first witness of the sentencing hearing, an FBI agent, described for the court a photograph that showed a young Khadr preparing a landmine.

The agent also demonstrated how an F1 hand grenade works and screened a video showing a U.S. military vehicle being blown up by the kind of landmine Khadr and his cell planted.

Khadr later pointed out the location of the planted mines, and they were neutralized.

A military agent said Khadr was co-operative during interrogations in 2002 but was "cold and callous" and "almost bragging" when he discussed his role in killing Speer.