GUYSBOROUGH, N.S. -- An inquiry investigating why a former Canadian soldier fatally shot three family members and himself heard Thursday from a firearms official who said she would have rejected Lionel Desmond's firearms licence had she known more about his severe mental illness.

Lysa Rossignol, operations manager for the Provincial Firearms Office in New Brunswick, told the inquiry she knew nothing about a December 2015 letter recommending Desmond for admission to a residential treatment program for people suffering from post-traumatic stress disorder.

The letter, from an operational stress injury clinic in Fredericton, said Desmond was struggling with PTSD and major depression, which is why he required intervention to stabilize his mental health.

The provincial court judge overseeing the inquiry, Warren Zimmer, read portions of the letter into the record, including the following: "Client continues to struggle with disabling symptoms of PTSD that directly affect his social and occupational functioning."

Though Desmond was not considered at risk for aggression or violence, the letter states he had "significant problems functioning in daily living."

Zimmer then asked Rossignol for her opinion.

"I realize you didn't have this information," the judge said. "In the context of all that you did know ... how would that affect your thinking about whether or not Mr. Desmond was a person that was still suitable to possess a firearm?"

Rossignol replied: "If our office would have been privy to this letter, it would have changed the outcome of his licence."

The inquiry has heard Rossignol reinstated Desmond's possession and acquisition licence on April 18, 2016.

On Jan. 3, 2017, Desmond bought a Soviet-era SKS 7.62 carbine, which he used later that day to kill his 31-year-old wife Shanna, their 10-year-old daughter Aaliyah and his 52-year-old mother Brenda inside the family's home in Upper Big Tracadie, N.S. He then turned the gun on himself.

Zimmer told the inquiry he wanted to draw attention to the value of updated medical information for authorities dealing with people like Lionel Desmond.

Earlier in the inquiry, the judge noted that provincial and federal health officials seemed to be operating in "silos" that prevented them from sharing key information.

"There appears to have been a real need for interventions ... to create stability (for Desmond)," Zimmer said.

The inquiry, which started last month, has looked into the support Desmond and his family received from mental health and domestic violence services. It has now turned its attention to how the former infantryman managed to maintain a firearms licence despite multiple run-ins with police.

On Thursday, Rossignol testified she and a colleague were tasked with reviewing Desmond's licence after RCMP officers were dispatched to his home in Oromocto, N.B., on Nov. 27, 2015.

At the time, Desmond's wife Shanna told police she had received texts indicating her husband was preparing to kill himself by using a rifle he kept locked in his garage.

Desmond was later arrested under the province's Mental Health Act, his weapons were confiscated by the RCMP and his firearms licence was suspended during a firearms office review that included a written medical assessment from a doctor.

Rossignol said the brief assessment from Dr. Paul Smith indicated Desmond was "non-suicidal and stable," and the doctor concluded he had "no concerns for firearms usage with appropriate licence."

That assessment echoed a similar appraisal made by another doctor in 2014. That doctor was asked for his written opinion after Desmond failed to note his PTSD diagnosis when he applied to renew his firearms licence earlier that year.

"He has no problem with Mr. Desmond possessing firearms," Rossignol said, reading from an investigation report prepared in December 2014. "He advises that Mr. Desmond has no psychosis and has never mentioned self-harm or any violent ideation."

Rossignol told the inquiry the medical assessments, though brief, gave her the assurances she needed to reinstate Desmond's licence in 2016.

However, she confirmed the forms the New Brunswick office used for firearms licence applications and renewals were changed a month after the shootings in eastern Nova Scotia.

Derek Eardley, the province's chief firearms officer from 2014 to 2017, testified that the new forms require doctors to provide more information when asked for an assessment.

He confirmed the Desmond case prompted the change in February 2017.

"It was definitely a big driver," he said.

-- By Michael MacDonald in Halifax

This report by The Canadian Press was first published Feb. 20, 2020.