The bag, packed with toiletries, a change of clothes, cash and bank documents, was never pulled down from the shelf.

Weeks after Mrs King, 67, was brutally killed by her husband in 2001 her daughters found the case as they sifted through belongings at the couple's Campbell home.

For Lisa Sforcina, it was one of the most disturbing discoveries in the aftermath of her mother's death.

"It was a very sobering moment for all of us," Ms Sforcina said. "It was a realisation of how scared she was; we had no idea about the suitcase.

"That day was horrendous."

It was one of countless difficult days Mrs King's loved ones endured as they came to terms with her murder and navigated a criminal justice process her daughter said was "a never-ending horror story".

Now, as the family prepares to mark the 15th anniversary of Mrs King's death on October 10, Ms Sforcina and her Canberra-based sisters Joanne Craigie and Mary Balzary have chosen to speak up to raise awareness of domestic violence.

Their mother's experience of abuse ended in violent murder, but began years earlier in far more subtle ways.

Her husband of 11 years, Maurice Dixon King, whom she married after her five children had left home, was a former army engineer who never drank or smoked.

Mrs King – a "quiet achiever" remembered as smart, loved and well-respected – once told her daughters before the pair were married she planned to leave him.

King later learnt of her plans and their mother later said she'd decided to stay.

"It was at that point we were all really concerned and thought, 'That doesn't sound right'," Ms Sforcina said.

"She was very, very private. We all asked her many times if she was worried about her physical safety and she said 'No, no, no'."

The family's doubts persisted as troubling signs emerged of King's controlling behaviour in the years to come.

"She couldn't leave the house without him going with her. He'd walk the dog for 15 minutes a day and that was the only window we could speak honestly with Mum.

"He basically kept an eye on her, accompanying her on any appointments he could. If she did go on her own, he went through her purse, and tracked the mileage on her car."

The morning she died, Mrs King spoke to Ms Sforcina, who confirmed she'd deposited money into her mother's bank account so she could buy a car.

"She was quietly trying to set herself up so she could live with dignity once she left. She had to leave on her own terms."

Hours later, Ms Sforcina's brother-in-law had called with news her mother was dead.

Police found Mrs King lying in a pool of blood on the Cobby Street home's lounge room floor, her head battered and skull broken.

King was charged with her murder but in June 2003 he was found unfit to plead. He died by suicide in 2005.

Ms Sforcina said the subsequent criminal proceedings were unfamiliar and traumatic, and prompted the family to lobby hard for legislative reform in the ACT.

"The whole process of going through the court was a never-ending horror story, really. At no point was that about our mum, it was completely about him, and what he did, and what was going to happen to him."

Ms Sforcina said education was key to boosting awareness of domestic violence, helping victims, and keeping the problem firmly on the national agenda.

"I don't believe that anybody would not know someone experiencing domestic violence, they just might not have heard anything.

"It's hard, people don't want to talk about it. We don't particularly want to talk about it. Before all this happened we weren't exposed to it, you think, 'It's not going to happen to us'."

If you or someone you know is affected by domestic or family violence, call the ACT Domestic Violence Crisis Service 24-hour crisis line on 6280 0900. In an emergency, call 000. See helpstopdv.org.au.