HALIFAX -- The Nova Scotia government says it will call an inquiry into the deaths of a former soldier and his family, nearly 12 months after the horrific bloodshed stunned a rural community and sent shock waves across the country.

Dr. Matthew Bowes, the province's chief medical examiner, recommended the fatality inquiry on Thursday, calling the deaths in Upper Big Tracadie, N.S., an "unimaginable tragedy."

On Jan. 3, 2017, retired corporal Lionel Desmond shot his wife Shanna, 31, their 10-year-daughter Aaliyah and his 52-year-old mother Brenda, before turning the gun on himself. Desmond had been diagnosed with PTSD and post-concussion disorder after completing two difficult tours in Afghanistan in 2007.

In a letter to Justice Minister Mark Furey, Bowes said the inquiry is necessary to "compel evidence and make recommendations for change."

"There are a number of provincial issues that can only be thoroughly canvassed through the mechanism of an inquiry," he said.

A spokesman for the Justice Department said the minister has committed to holding the inquiry, with the terms of reference and the judge set to be announced in the new year.

Two of Desmond's sisters, twins Chantel and Cassandra, have led a high-profile campaign calling for an inquiry, saying their brother did not get the help he needed.

"It's about time," Chantel Desmond said in an interview Thursday. "They must have thought we weren't going to fight.

"We're fighters and we're not going to give up," she said. "I think they really felt it would get nowhere and get swept under the rug but this is just the beginning."

Desmond said she's hopeful the inquiry will shed light on "what the province did, and what they didn't do" as well as the federal government's mistreatment of veterans.

"It took my family to go through it," she said. "I lost my family and now I'm worried about trying to help other families."

At a news conference, Bowes said he concluded that the inquiry is warranted after speaking with members of the Desmond family and carefully reviewing the circumstances of the deaths.

"Our entire province was shocked by the deaths of Lionel Desmond and his family," he said. "There have been many questions raised by the family and the public relating to how this could have happened and whether anything could have been done to reasonably prevent these deaths."

While cautious not to presuppose the focus of the inquiry, Bowes 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.

Bowes said the inquiry will examine whether there is a "tangible connection between the deaths and the appearance of a failure of policy or practice which if corrected is likely to prevent future deaths of this same type."

"It's my hope that the public nature of the inquiry and its final report will drive change," he said.

Such investigations are rare in the province. The last time a fatality inquiry was held in Nova Scotia was almost 10 years ago.

Trev Bungay, a retired soldier who served in Afghanistan with Desmond, questioned why it took almost a year to recommend an inquiry into the horrific murder-suicides.

"It's about time," he said in an interview from Fredericton, N.B., adding that Ottawa and the province "wasted a lot of time blaming each other and trying to figure out whose fault it was."

Still, Bungay said he's hopeful the inquiry will provide some badly needed answers for the family, as well as ensure better services are in place for veterans in the future.

"At least the family can have some sort of closure. For them this has been a nightmare," he said. "They want answers and this is how to get them and more importantly how to stop this from ever happening again."

Family members say Desmond was a radically changed man when he was medically discharged and returned home 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.

Several veterans' groups and individuals have also called for an inquiry, including Vets Canada and Wounded Warriors Canada.

Veterans' advocate Peter Stoffer said Thursday there are several questions the inquiry will need to address.

The former Nova Scotia NDP MP said the inquiry will need to examine Desmond's transition from military to civilian life, including gaps in services provided by Veterans Affairs Canada and the province.

"The number one recommendation would be that nobody leaves the military or for that matter the RCMP until all support systems are in place," he said. "The services need to be in place before the uniform comes off."

Stoffer added that the inquiry must be open and inclusive.

"It should have access to all the information that it asks for in order to determine, if it's possible, what happened and where lessons can be learned so that this tragedy will not happen again," he said. "I'm just hoping at the end of the day the inquiry will provide some of the answers the family is asking for to give them some comfort and most importantly give them some closure."

More than 130 serving military personnel have taken their own lives since 2010, according to National Defence.

In October, Ottawa promised to improve support for military personnel through a new suicide prevention strategy, which focuses on easing the transition from a military career to civilian life.