On the 6th of 7th of August 1984, Margaret (35) and Seana (9) Tapp were murdered in their beds in their home on Kelvin Drive, Melbourne, Australia. Margaret was Seana's mother and the two lived alone in their home in Ferntree Gully. Both victim's cause of death was strangulation via a piece of rope, although signs of a beating were also present on Margaret, and Seana had been sexually assaulted before death. The mother and daughter were discovered on the 8th of August in their nightwear in their beds. Margaret was found with her hands crossed with her right over her left and resting on top of her chest, just covering the lower part of her neck. It's very possible she was posed in this way, as it's unlikely she'd come to rest in that way as she was killed by strangulation.
Margaret was a very intelligent woman, who worked as a nurse and also a part-time law student. She was also considered to be a very beautiful woman and she had many admirers.
At around 11 pm on the 6th of August, a neighbour heard a sound like a muffled scream, and around midnight (7th) other neighbours heard Seana's normally quiet spaniel bark and howl. On the morning of the 7th Tony Blackwell, a young man going out with Margaret's sister picked up the newspaper in the driveway, knocked on the door and left, puzzled that Margaret's car was there but no one was home. Then around 6 pm one of Margaret's admirers, Jim, came around to go to the opera - a date she Margaret had arranged. When no one answered, he opened the door and discovered Margaret dead in her bed, with a book beside her. He then discovered Seana and raised the alarm with a neighbour. He had gained entry to the house via the backdoor due to a faulty lock.
Clues at the scene included Semen found on Seana's night dress (however this may be problematic due to the forensic collection and storing techniques at the time), two hairs, and Dunlop Volley tennis shoe prints in her mother's bedroom and the bathroom. The shoe size did not match that of Margaret, Seana, or anyone else the police could place at the scene. They concluded the killer must have been wearing the Volleys.
Through DNA multiple people have been ruled out, including the man who discovered the bodies. Interestingly, a pizza was found in the Tapps oven - though I can't find whether the oven was on (perhaps keeping food warm) or off (as if Margaret or even the killer forgot it was there.) One theory is that the killer may have spent some time in the house and began to cook a pizza for himself, but was spooked when Tony Blackwell called to the house in the morning.
One person I find of interest is the young man whom Margaret would pay to mow the lawn. He was a member of a family that lived in Kelvin Drive in the 1980s. The neighbours were concerned about him mowing Margaret's lawn and cleaning her car because of the young man's strange behaviour and sexually aggressive remarks he'd made to other women. As of 2010, he, his three brothers, and his stepfather have not been eliminated by forensic testing. A sister of the same family lived in a caravan beside the house with a boyfriend later jailed for rape. What intrigues me about the young man is that he would have known the family and may have known their routine and even the layout of their house. He also may have known about the faulty lock to gain entry, and he would have many opportunities to observe Seana - who seems to be the intended target. As his sister lived in a caravan beside the house, he also would have had a reason to be in the area had he been spotted.
An Affair and Conflict
It was also discovered during the murder investigation that a Doctor had provided the Tapp's with their home. The Doctor was married, and it's known that Margaret and he were having an affair. Police discovered the doctor's wife had known about the long-running affair and that she and Ms Tapp had argued about it several times. The doctor's wife also told police that Margaret had once turned up to beg the Doctor to leave the marital home and come and live with her. On this occasion (according to the Doctor's wife) Margaret had thrown a rock through their window, stripped naked, and then lay down on the front lawn. The Doctor had calmed her down and drove her home.
Before Margaret and Seana's murders, the Doctor died in a traffic accident, however, there was an argument over ownership of the house. The doctor's wife fought to take ownership, though in the end Margaret was awarded half and then purchased the other half from his estate.