HALIFAX -- As Nova Scotia's health system continues to grapple with the disturbing case of Lionel Desmond, two of his sisters have come forward to shed new light on what happened to the former Canadian soldier, who was transformed from a fun-loving family man to a paranoid killer after serving two tours in Afghanistan.

"His shell came back, but that beautiful soul inside of him became a dark cloud," Cassandra Desmond, one of his twin sisters, said in one of her first in-depth interviews this week.

It's been almost six months since the murder-suicide in Upper Big Tracadie, in which Desmond killed his wife, mother and daughter.

Even though the killings fuelled a national debate about how Canada treats former soldiers, sailors and airmen living with PTSD, the RCMP and government officials have said little about a case that has raised questions about what happened to Desmond, and how such a tragedy can be prevented from happening again.

On Friday, a senior Nova Scotia health bureaucrat publicly apologized to the Desmond family for miscommunication that led to a delay in setting up a meeting to discuss an internal review of the man's interaction with the health-care system.

"I did (apologize) in the sense of the frustration that they are experiencing in being able to come together with us," said Colin Stevenson, the Nova Scotia Health Authority's vice-president of quality. "It was miscommunication on my part."

Earlier in the week, Cassandra and her twin sister Chantel demanded a judicial fatality inquiry, and they spoke at length about their brother and his struggles with his mental illness.

Diagnosed with post-traumatic stress disorder and post-concussion disorder after his deployment in 2007, Desmond was 33 when he fatally shot his 52-year-old mother Brenda, his 31-year-old wife Shanna, and their 10-year-daughter Aaliyah in January. He then took his own life in the family's rural Nova Scotia home.

Before he was deployed to Afghanistan, Desmond was a healthy, animated man with an infectious sense of humour and an endless capacity for hard work, Chantel Desmond told The Canadian Press.

"He was one of the happiest guys," she said during an interview at her sister's home in Antigonish, N.S. "You could be down in the dumps and he would lift you up. He was awesome."

Cassandra Desmond was more emphatic, saying Lionel was the "clown of the family" and a definite ladies man.

"He was always imitating somebody or something," she said, adding that his broad smile matched that of their mother Brenda. "There was never a dull moment around him ... I think of Lionel and I laugh and I smile."

As a young man, Lionel Desmond met Shanna Borden when the two were attending high school, not far from where they would later live in Big Tracadie.

"He loved her," said Chantel Desmond. "They were good."

He enlisted in the military soon after graduating from high school and would later be promoted to corporal as a member of 2nd Battalion, Royal Canadian Regiment, based at Canadian Forces Base Gagetown in New Brunswick.

Lionel and Shanna Desmond's daughter, Aaliyah, was born shortly before he left for Afghanistan in 2007.

A well-circulated photo from that time shows Shanna Desmond holding their infant daughter close to her smiling face as her husband snuggles in close, his right cheek touching Aaliyah's forehead.

"Aaliyah, she was his life," said Cassandra Desmond. "My mother, that was his best friend."

However, Lionel Desmond was a radically changed man when he returned home from Afghanistan, and not much had changed by the time he was medically discharged in 2015, his sisters said.

They talked about how his sense of humour had dimmed and, more importantly, how he seemed withdrawn and in a defensive posture much of the time.

"He was still in combat mode," Chantel Desmond said. "At dances, he would be spinning on the floor and thinking he was still in combat. Anything could set him off. He would wake up in cold sweats ... He would back into corners, have his back against the wall."

And then there was his sense of guilt. In his personal journal, he wrote that the people he was fighting in Afghanistan "were people, too."

Trev Bungay, a retired soldier who served in Afghanistan with Desmond, has said Desmond was a great soldier who did his job well, but he said it was a stressful deployment marked by heavy combat, many casualties and decidedly grim duties, including the body-bagging of dead Afghans and Taliban fighters.

The carnage on the battlefield left its mark on Lionel Desmond.

Cassandra said his wife, Shanna, could calm him down when certain sounds and smells would trigger a PTSD flashback. Even the rustling of the leaves in a breeze could set him off, even though he spent a lot of time in the woods.

"When my brother came back, they did nothing for him," Chantel said, referring to the military and Veterans Affairs Canada. "He had to wait for his pension. He had to wait for everything. They was so much stress on him."

Despite his struggles, Lionel Desmond and his wife worked hard to get help. He spent three months receiving some sort of treatment at a facility in Montreal. He was supposed to be there six months. The couple had appointments with many doctors. There was marriage counselling. And Lionel had a prescription for medical marijuana.

Some days, he seemed like his old self. There were many other days when he would mumble to himself and withdraw.

But it was clear that he was well aware of what he was dealing with.

"My brother was no stranger to his sickness," Chantel said, noting that his Facebook page includes many entries in which he talks about wanting to be well again.

"I'm truly sorry for freaking out at my wife (and) daughter and people who know me," one entry says. "I'm not getting a lawyer. I'm getting my life back."

That was on Dec. 3, a month before the shootings.

"I apologize for anything out (of) my control," he wrote. "I will fix it, if not I'll live with it."

At one point during his deployment, he hit his head on an light armoured vehicle after falling off a wall, and was later told he had post-concussion disorder as well as PTSD.

"That (explains) my jealousy towards my wife and being over-controlling and (my) vulgar tongue towards my family," he wrote on his Facebook page, in which he called himself Lionel Demon.

His twin sisters said this week they were keen to get the recommendations from the Nova Scotia Health Authority's quality review, but they made it clear they have grown frustrated by delays and what they perceive as a lack of disclosure and accountability.

Stevenson, spokesman for the authority on the Desmond file, confirmed Friday that the review was completed in March. However, he said he has been unable set up a meeting with relatives because of confusion over who would be represented.

Meanwhile, the province's medical examiner, Matthew Bowes, has said he is also waiting to see the results of the quality review, which Stevenson said will not be released to the public, even though the authority has the option of doing so if all personal health information is deleted.

Stevenson said the authority wants to ensure those taking part in such reviews have the "confidence that they can come forward ... without the fear of the information they shared as being made public."

"Anybody can ask, but we're not actually obligated to release," he said.

Stevenson also noted that the results of the review include only recommendations with no accompanying report.