Together they learned the military trade, grew up, became best friends. Matters stood beside Seguin at his wedding as his best man, and he was the godfather of Seguin's children.
On Wednesday, Warrant Officer Seguin handed Memorial Cross medals to the mother and sister of his comrade-in-arms, who died in a confrontation with RCMP on his rural property near Prince George, B.C., a year ago.
Matters was in treatment at the time for post-traumatic stress disorder, and his death focused attention on the struggles of current and former soldiers who have served in conflict zones overseas.
"We did everything together through our military career," Seguin said after the ceremony and after meeting his best friends' family for the first time.
Seguin said he believes Matters really began to struggle after a back injury he suffered in Bosnia prevented him from training to take part in Canada's combat mission in Afghanistan.
"I never realized it was post-traumatic stress," Seguin said.
"I think that's when he started having the symptoms but all I could figure at the time was that, I just thought he was embarrassed and ashamed that he wasn't able to do the training with us and go to Afghanistan with us."
Matters served in the Canadian Forces for 15 years, and Seguin said he was glad to finally meet his friend's family.
"Every evening we've sat around and I've told them some of our funny stories that we experienced together," he said. "Letting them know what a good friend and fun soldier he was."
For several years, Matters's family noticed his struggles but by the time an RCMP emergency response team was sent out to his home last September, he was in treatment for PTSD.
The Memorial Cross is awarded for soldiers whose deaths are linked to their military service, and Matters's sister, Tracey Matters, said the medal is an acknowledgment to the family that PTSD was a major contributing factor in her brother's death.
"As a family, we are grateful to the Canadian government for recognizing the sacrifice that Greg, and our family, have made," she said in an email to The Canadian Press.
She said the family hopes his death may spur changes that will help other soldiers.
"We believe it is time for Canada to recognize its 'Unknown Fallen,' the men and women who are injured physically and psychologically by military service, and who, when they are discharged, continue to struggle and suffer," Tracey Matters said.
She said her brother was one of those soldiers.
"Many of these individuals die alone and their death is never recognized as being due to their military service. Their names are not written in the book of remembrance in the House of Commons. Their names are not inscribed on public memorials. They are not part of the highway of heroes, yet their injuries caused, or significantly contributed, to their deaths."
British Columbia's Independent Investigations Office cleared RCMP of wrongdoing in the shooting, but the Matters family said many questions remain.
A coroner's inquest into the shooting will take place next month.
"We hope that through Greg's death, we have been able to raise awareness of PTSD within and outside of the military and the lack of support and understanding our soldiers and veterans have to endure," Tracey Matters said.
Seguin said he believes the military has done a great deal since the war in Afghanistan to make treatment available to soldiers, and to recognize the signs of struggle.
And he said he plans to come back to B.C., so his 15-year-old twins can meet the family of their godfather.
- By Dene Moore in Vancouver.
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