Four men and three women are charged with deciding Omar Khadr's fate when his long-awaited military commission trial begins in Guantanamo Bay Thursday.

The jury of seven U.S. military officers was chosen Wednesday after eight other potential jurors were dismissed following defence and prosecution objections.

The Canadian Press reports that most were excused after defence challenges of their impartiality.

"Today is one of the very few days that has gone in Omar Khadr's favour at Guantanamo Bay," said the head of Amnesty International Canada Alex Neve.

The seating of the jury means prosecution lawyers can now focus on their opening argument that will set the trial in motion.

CTV legal analyst Steven Skurka said the fact that all of the jurors will be members of the U.S. military raises questions about whether Khadr will get a fair trial -- but that doesn't mean it won't play to his advantage.

"I think it's possible that Omar Khadr's going to win this case," Skurka told CTV News Channel on Wednesday morning.

"These jurors will recognize that this case is under the international spotlight, they'll recognize indeed that Omar Khadr was a child soldier at the time of this alleged murder, 15 years old at the time."

With a lack of forensic evidence and not a single eyewitness to the crime, Skurka said the jurors may find the evidence unreliable.

Col. Patrick Parrish, the judge presiding over Khadr's trial, has told jurors that they will be able to funnel questions to witnesses through himself.

But the judge will decide if their questions are legally appropriate before they are put to witnesses.

Reporting from Guantanamo Bay, CTV's Daniele Hamamdjian said that when Khadr appeared before jurors Tuesday, he was agreeable and dressed in a suit, in contrast to prior appearances in the military court in which he openly dismissed his upcoming trial as a sham.

"This is the first day of Ramadan, so there were concerns he wasnt going to show up, but he did," Hamamdjian told CTV News in a phone interview Wednesday.

"We are told that whether he shows up or not, the trial will continue with or without him."

The 23-year-old Canadian citizen is facing five charges, the most serious of which is murder in violation of the law of war.

U.S. prosecutors allege that the teenaged Khadr threw a grenade that killed U.S. Sgt. Chris Speer in July 2002. Toronto-born Khadr has been in U.S. custody ever since.

In order to convict Khadr, at least five jurors will have to agree. Should they find him guilty, at least six of the seven jurors must agree in order to sentence him to life in prison.

This is the first such trial under the administration of Barack Obama, who campaigned on a promise to end the process altogether.

With files from CTV's Daniele Hamamdjian and The Canadian Press