Marea Yann had settled into her evening routine on September 29, 2003. Relaxing on the couch ready to enjoy her favourite TV shows, the grandmother had much to look forward to. Her 70th birthday was just a few weeks away and celebrations were being planned with her three children, grandkids, and hordes of friends.

Tragically, the festivities never eventuated as Marea was bludgeoned to death with 22 blows. Found the next morning, detectives called her brutal murder one of the worst crime scenes they had ever seen.

Two decades on, Marea's family tell New Idea that that night still haunts them.

"My sister Ronda called me crying," Marea's son Jeff, 65, shares. "She said I was to go to the police station and Mum had been killed. I didn't know if it was a car accident or what."

Driving to Marea's home in Healesville, Victoria, Jeff saw all the police tape and quickly realised something more sinister had happened. When the officer in charge told him his mum had been murdered, Jeff couldn't believe it.