James Rollins was confused. The carpenter was at the front door of 13 Kelvin Drive in Ferntree Gully, a town 30km east of Melbourne's CBD.
Rollins had arranged to pick up Margaret Tapp at 6pm for an evening at the opera, but the blinds were closed and she wasn't answering the door.
Her car was in the driveway, suggesting she was home, although that morning's newspaper was still sitting on the stoop.
His confusion was shared by two other visitors to the house earlier that day: Margaret's sister's boyfriend, who had attempted to visit around noon, and the young girl next door, who came around that morning to walk to school with Margaret's daughter, nine-year-old Seana Tapp.
Rollins had been to the house many times before, and remembered the lock was broken on the back door. He let himself in, and called out. He then made his way into Margaret's bedroom. He noticed her doona was raised and crumpled, and thought she was asleep.
"I could see her face from the mouth up," he said in his police statement. "I put my hand on the doona and said, 'Marg'.
"At this stage I could see her complexion was quite pallid and I thought she was sick."
He pulled the doona down a few inches.
"Her hands were crossed with her right over her left and resting on top of her chest, just covering the lower part of her neck," he said. "I don't think I saw blood, but it was blood-coloured.
"I thought Marg was dead. I then rang police.''
Remembering nine-year-old Seana, he ran into her room and made an even more gruesome discovery. The young girl had been murdered, in a much more brutal manner than her mother. Both had been strangled to death; fibres found around their necks suggests some form of rope was used to kill them both.
Margaret and Seana Tapp were murdered in the late hours of August 7, 1984, and after 35 years, the horrific crime remains unsolved. While other cold cases in Australia have received mass media coverage over the years, the Tapp murders have been largely overlooked.
Initially there were only five small newspaper articles written about the case, and it quickly slipped down the priorities list of overworked detectives.
Part of the reason this case was overlooked and has proven impossible to crack was the long list of men connected with Margaret.
Margaret Tapp led an active social life since getting divorced in 1979, and was dating multiple men at the time of her death.
This is another reason why the case didn't receive much media attention – often it is the efforts of family and friends that garners press, but Margaret's parents were strictly religious and private people. They didn't want the details of their daughter's active sex life to be dragged through the papers.
A LONG LIST OF PEOPLE TO INTERVIEW
Margaret's ex-husband Don was quickly cleared — the couple had a divorce free of acrimony. James Rollins, who discovered the bodies, was also cleared once police questioned him.
Margaret worked as a nurse at various hospitals and had entered into relationships with six different medical professionals over the past few years, including one married doctor with whom she had a long affair.
This particular doctor was so besotted by the 35-year-old that he purchased a house for her to live in rent-free, so they could carry out their affair in relative secrecy — this was the Ferntree Gully address she was murdered in.
When the doctor was killed in a car accident in 1983, Margaret claimed ownership of the house, contesting the will.
Their affair was something of an open secret; the late doctor's long-suffering wife told police that Margaret once arrived at their house and attempted to convince her husband to come and live with her.
When he rebuffed her offer, Margaret threw a rock through their window, stripped naked and laid in the front yard. Telling his frightened wife and child to hide in the bedroom, the doctor drove her home.
Despite such high-octane drama, the courts sided with Margaret. She was awarded half of the Ferntree Gully house, and bought out the remainder from his estate.
There were many other suitors. There was a 19-year-old who met Margaret at a disco in late 1983 and had a brief fling with.
Margaret was also studying law at Monash University, and met a student there. They slept together four days before her death, and lunched on the day she was murdered.
There was also the married driving instructor. Margaret was attempting to get her truck license and a lovestruck friend was teaching her for free, as a thinly-veiled excuse to spend time with her.
Police questioned him about their relationship but he was not considered a suspect.
Other people of interest had less personal relationships with her, but were still on the police interview list.
A relative's boyfriend had been at the house earlier that day and was therefore questioned. The owner of a red Ford ute that was parked near the Tapp house was also a person of interest, although police never discovered whose vehicle it was.
A troubled teenage boy who lived on the same street as Margaret had a reputation in the neighbourhood for making sexually-charged comments to females. His name was mentioned to police as a possible person of interest, but he was never formally questioned. Neither was his sister's boyfriend, who was living nearby.
A person of great interest in the Tapp case was a former police officer named Ian Cook, now deceased. Cook was much older than Margaret, and was a friend of her parents.
He was the first person Margaret's sister Joan mentioned to police as a possible suspect, explaining that Margaret had found his romantic overtures unwelcome, as well as his frequent visits to the house.
Moments after the murders were discovered, Cook surprised all by turning up to the house. Astonishingly, he was allowed to enter the active crime scene, ostensibly to collect a book he had left there.
When Cook was later questioned about his link to Margaret, he refused to give his fingerprints to police.
RED HERRINGS AND FALSE ARRESTS
In 1984, DNA testing wasn't a possibility. Nevertheless, the police collected one key piece of evidence that may prove to be quite useful — a semen stain on Seana's nightgown. Horrifically, the nine-year-old was sexually assaulted during the murders, and while Margaret's active love life was the initial focus of investigations, it is clear from his actions that the murderer had pedophilic tendencies.
Margaret's personal life, and theories of a spurned lover seeking revenge, had obscured the real motives at play.
Many fingerprints were lifted from the house, but all belonged to family members or friends. Two different hairs were found on Seana's bed, but this proves little in isolation.
Footprints in Margaret's bedroom and bathroom, made by a large pair of Dunlop Volleys, provided the main physical clue to the murderer in 1984. As technology improved throughout the years, however, this DNA evidence from the semen stain became the biggest chance of solving the crime.
In 2008, police thought they had a breakthrough. A prisoner, Russell John Gesah, was charged with the murders, after the semen stain was found to be a DNA match.
"I am very pleased," Tapp's father Alan Nelson told the Herald Sun shortly after the arrest. "We have waited 24 years for this day.''
Police announced the arrest, but were forced to backtrack and drop all charges just two weeks later after it was discovered that the DNA samples were contaminated.
Gesah's DNA, lifted from another item of clothing, was tested in the same lab, on the same day, as the Tapp exhibit. The samples were mixed, and the positive results just meant that Gesah effectively matched his own DNA.
More worryingly, it meant that any suspect who had been cleared of the Tapp murders previously may have been tested against the wrong sample.
It also meant that any DNA link to the Tapp exhibit made in the future could be argued as inadmissable. This was a huge blow to the case.
The Dunlop Volley footprint was, once again, the only reliable piece of physical evidence the police had.
TERROR IN THE TOWN
Shauna Kettlewell lived on Kelvin Drive when Margaret and Seana Tapp were murdered. She was the same age as Seana, shared the same name, albeit with different spelling, and went to Brownies like Seana — although the two girls were in different troupes.
She believes the Brownies connection could be the key to solving the murders. Five years ago, she attempted to investigate the murders herself, but was blocked when she attempted to look into people connected with Seana's Brownies troupe "that were known to have had an unhealthy interest in the little girls that were their charges".
"The fallout in Seana's troupe was horrible and devastating," she tells news.com.au. "Brownies and Guides are not as popular today, and the Scouting movement in general is suspicious of outsiders," she explains, adding that even as a former member, she could not get any answers.
Herald Sun crime journalist Andrew Rule hints at a similar connection, ending a long report on the murders, in which he interviewed many key players, by writing: "Whoever goes to see potential suspects might check their shoe size … and whether any of them ever had a link with the Girl Guides or Brownies."
Kettlewell tells news.com.au of the shock and sadness around the murders, and how rumours flew between parents that lived on the street. At the time, the details of the rape were understandably kept from the children, but they sensed the unease in the air.
"What happened to Seana in particular was so confronting that I was just told she had died," Kettlewell says.
"To children, it's hard to understand that death is permanent. Many of us who knew Seana or went to school with her developed post-traumatic stress disorder later.
"A few of Seana's classmates scratched her out of the 1984 Wattleview Public School class photo as a way of coping."
Kettlewell started insisting that she be able to sleep with the light on — the only respite for a traumatised nine-year-old girl living on a street where nine-year-old girls were suddenly being murdered in the night.