HALIFAX -- Nova Scotia's inquiry into the shooting deaths of an Afghan war veteran and his family could have sweeping implications for ailing former soldiers, veterans' advocates say.

Lionel Desmond -- diagnosed with PTSD after two harrowing tours in Afghanistan in 2007 -- shot his wife, daughter and mother before turning the gun on himself on Jan. 3, 2017.

The province's long-awaited decision Thursday to launch a fatality inquiry -- and Ottawa's commitment to provide its "fullest support" to the probe -- will put a spotlight on how injured soldiers are transitioned to civilian life across the country.

Veterans Affairs Minister Seamus O'Regan said Friday the federal government will work with the province on the inquiry to prevent a similar tragedy from happening again.

"Very difficult circumstances led to this investigation and it is important we work together to ensure they do not re-occur," he said in a statement. "We are committed to co-operate with the province."

Veterans' advocate Peter Stoffer said that while the inquiry will focus on Desmond, the findings and recommendations will influence "veterans right across the country."

"This will have national implications for the government in the way they operate and for the provinces and territories," the former Nova Scotia MP said Friday. "Hopefully the transition process exiting the military or RCMP will be much more enhanced."

Family members say Desmond was a radically changed man when he was medically discharged, and returned home to Upper Big Tracadie, N.S., in 2015. They say his outgoing sense of humour had dimmed and, more importantly, he seemed withdrawn and in a defensive posture much of the time, as if he was still in combat mode.

Within hours of the killings, relatives came forward to complain the retired corporal did not get the help he needed to cope with civilian life.

Retired master warrant officer Barry Westholm called the Desmond family deaths "a national tragedy."

"If Lionel had a place to call, a human being that could say, 'OK Lionel come on back to the base and let's sort you out,' maybe this tragedy could have been prevented," he said Friday. "It takes something like this to make them do something."

Westholm served as a sergeant major for the Joint Personnel Support Unit -- an eastern Ontario unit which provides support and programs for ill or injured soldiers -- before resigning in protest.

He said the inquiry should examine how injured soldiers are prepared for civilian life and monitored once they're released.

Though he's cautiously optimistic the inquiry could spark changes for injured soldiers, Westholm said it's already clear what's needed.

"That's what's driving me bananas. They've got everything they need except for leadership," he said. "All the answers are there, the reports are written, the people are there."

"You've got the entire Canadian Armed Forces and Veterans Affairs, that's tens of thousands of people and billions of dollars at your beck and call, and you can't get a person transitioned out of the military correctly. There is no excuse except leadership."

Dr. Matthew Bowes, the province's chief medical examiner who recommended the fatality inquiry, said the apparent lack of co-operation between government agencies will likely be a key aspect of the terms of reference.

"I was very much struck by the fact that there were many government agencies that touched on Mr. Desmond's life and I would take the view that the interconnection between all of those may well have been better," he said Thursday. "It's my hope that the public nature of the inquiry and its final report will drive change."

Trev Bungay, a retired soldier who served in Afghanistan with Desmond, said one of the biggest issues is a lack of follow-up with injured soldiers once they leave the military.

"The mistake is once you leave those facilities there is no contact unless you make it," he said. "What people don't understand is if someone has an operational stress injury or PTSD, they have it for life."

Bungay, co-founder of Trauma Healing Centers -- a chain of facilities offering treatment for veterans, first responders and civilians suffering from PTSD, trauma and other issues -- said injured veterans need to be put on a lifelong treatment plan with regular follow-ups.

"If you get off that plan then you'll go downhill and struggle," he said. "But if you stay on it and you stay well, then you have a chance at living a great life."