Joshua Key, the first U.S. deserter with combat experience in Iraq to apply for refugee status in Canada, told the board he witnessed numerous atrocities committed by U.S. forces while serving eight months as a combat engineer.

Key, 27, said he was never trained on the Geneva Convention and was told in Iraq by superior officers that the international law guiding humanitarian standards was just a "guideline."

"It's shoot first, ask questions later," Key said of his squad's guiding principles. "Everything's justified."

Key is one of five members of the U.S. armed forces asking for asylum in Canada.

But the Oklahoma native is unique in that he is the only applicant that has combat experience in Iraq, said Key's lawyer, Jeffry House. The other are seeking asylum in Canada to avoid being sent there, he said.

"He has boots-on-the-ground experience about what the actual conduct of the war in Iraq is," House said outside the hearing.

With visible bags under his eyes, Key told the hearing he suffers from post-traumatic stress disorder and frequently has nightmares over what he witnessed in Iraq.

He recalled participating in almost nightly raids on homes of suspected insurgents in Ramadi and Fallujah as a member of the 43rd Combat Engineer Company.

He said that while the raids seldom turned up anything of interest, he often saw soldiers ransack the homes and steal jewelry or money, while superior officers looked the other way.

He also said several Iraqis were shot dead, and that they were cases of soldiers "shooting out of fear and inventing reasons afterward."

In Ramadi, Key said he saw the beheaded bodies of four Iraqis beside a shot-up truck and witnessed several members of the Florida National Guard kick a severed head "like a soccer ball."

Key also said he witnessed one of his "trigger happy" platoon's squad sergeants shoot part of an unarmed Iraqi man's foot off in Khaldia, a village between Fallujah and Ramadi. The man was sitting on a chair outside a store and had raised his foot as a sign of disrespect, he said.

Key added he was never questioned about the incident and was not aware of any charges being laid.

Keith Brennenstuhl, the IRB member overseeing the hearing, ruled at an earlier hearing that the board would not consider the legality of the U.S.-led invasion of Iraq.

Key also described seeing U.S. soldiers indiscriminately kick and scream at two hooded and naked detainees while escorting them to a grassy area to relieve themselves.

Brennenstuhl asked Key whether he received any interrogation training before dragging detainees out of their homes during raids.

"The only thing we were told was how to keep them quiet," Key said, explaining that soldiers cuffed prisoners' hands behind their backs and put hoods over their heads.

"Could they breathe?" Brennenstuhl asked.

"I guess it wasn't my concern," Key responded, adding that officers said the hoods were designed "to humiliate them."

Key, the father of four young children, told the hearing he joined the army for steady pay and medical coverage for his family. He said he initially went to Iraq as a willing participant because he believed U.S. intelligence claims that Iraq had weapons of mass destruction.

But Key became disillusioned with the war during his service and decided to abandon his contract with the army during a two-week leave from Iraq in November 2003.

He and his family lived on the run in Philadelphia before crossing the border at Niagara Falls, N.Y., on March 3, 2005.

Key now works as a welder in Fort St. John, B.C. He and his wife Brandi have four children between the ages of seven months and six years.

If returned to the United States, Key said he believed the army would "make an example" of him as a way to deter other possible deserters.

Lawyers from all parties will submit their written submissions in the coming weeks before the board rules on Key's application.