HALIFAX -- Over three years after the bodies of Lionel, Shanna, Aaliyah and Brenda Desmond were found inside a home in Upper Big Tracadie, Nova Scotia, a fatality inquiry is scheduled to begin hearing evidence on Monday.

Lionel Desmond fatally shot his wife, 10-year-old daughter and mother, before taking his own life.

Desmond was a retired corporal, who served in Afghanistan. His family says he had post-traumatic stress disorder – but never received the help he needed.

"This inquiry is looking at a couple of really important issues, one being the issue of post-traumatic stress syndrome and how the government responds and sometimes does not adequately respond to that growing problem,” says professor emeritus at Dalhousie University's Schulich School of Law, Wayne MacKay. “Secondly, and equally importantly, the issue of domestic violence and why the two are connected in this case."              

The inquiry will also look at whether Desmond should have been able to buy a gun.

"Why Mr. Desmond, in this case, was able to have a weapon that allowed him to engage in the unfortunate conduct raises questions of access to weapons and how people can get access to lethal weapons," says McKay.

The inquiry was originally slated to begin hearing evidence in November. However, the family of Desmond’s wife, Shanna, replaced their lawyer and asked for an adjournment – which the judge overseeing the inquiry granted.

When the inquiry is complete, Judge Warren Zimmer will file a written report with the court. However, the report will not contain any findings of legal responsibility.

"It's definitely the hope that change will come from this,” says McKay. “The idea behind it is to be preventive in the future. I mean, first of all, to get a clear picture of why the tragedy unfolded the way it did; but more importantly than that, what can be done going forward to not have anything like this happen again."

Meanwhile, the Desmond fatality inquiry will take place at the Municipal Building in Guysborough, Nova Scotia where evidence will be heard beginning on Monday. The inquiry is open to the public, with family from both sides expected to attend.