Mother and daughter killed in their home in suburban Melbourne, Australia in 1984. Both were strangled, young Seana (Shawn-uh, not See-Anna) had been viciously sexually assaulted.

https://www.theage.com.au/national/victoria/a-mother-her-daughter-and-a-murder-case-that-got-away-from-all-20100618-ymx2.html

Terribly sad case. It didn't get as much media coverage as some of Australia's more well known cases. Killer is still at large, although apparently the police have a new lead. 10 years ago some random criminal was named as the killer but turned out to be a massive DNA bungle.

Whoever it was, Margaret was just the obstacle he had to eliminate to be able to rape Seana. He was a paedo and had little sexual interest in adult women.

I'm a little upset with those in the media who keep calling Seana "See-Anna" instead of "Shawn-uh". It's such disrespect

A lot of people should know that Seana was bright enough that when most kids her age are in Grade 3, she'd been upgraded to Grade 4 at Wattle View Primary School.

The temporal perspective really hits you. For those of us who grew up In Melbourne's outer east, it still feels like yesterday... but then you remember that when Margaret and Seana were killed, there was still a "Sun" paper in the morning and a "Herald" in the afternoon. There wouldn't be a "Herald Sun" for over six years.

I think Seana was the intended victim. The attack on her was so much more brutal.

But my gut feeling tells me that the perpetrator first became familiar with the Tapps through Margaret since she had such an active social life and would have crossed paths with so many people. But that’s just my impression, not based on anything more than a gut feeling.