IN part six of The Chronicle's Unsolved Crime series, we speak with an historian who believes she has solved one of Australia's oldest unsolved murder mysteries.

A CRIME historian believes she has pieced together who was responsible for one of Australia's oldest unsolved murder mysteries.

Michael Murphy, 29, and his sisters, Norah, 27, and Ellen, 18, were murdered on December 26, 1898 near Gatton in the Lockyer Valley on the way back to their parents' property after a country dance was cancelled.

The trio had earlier spent the day at the Boxing Day races near Mt Sylvia.

Their brother-in-law William McNeill set out looking for them the following morning after they did not return home.

Toowoomba's worst unsolved crimes: Gatton murders: A crime historian claims to have solved one of Australia's oldest unsolved murders.

He followed their sulky's tracks along Tenthill Rd as they veered through sliprails into Moran's paddock, where Ghost Gully Produce is located today, where he came across the grisly murder scene.

Michael's body was found with his skull battered in, lying on his front, but with his head turned to the side.

His hands were folded behind the back and there was evidence his wrists had been tied up.

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A post mortem carried out at the time revealed Michael died as a result of a single rifle shot to the head with the bullet having entered behind his right ear.

Both Norah and Ellen had been tied up with handkerchiefs, repeatedly bashed and raped before being killed with several blows to the head.

The trio's horse was also shot in the head and lay near the women's bodies.

Crime historian Stephanie Bennett believes John Joseph Quinn was responsible for the triple murder on December 26, 1898 near Gatton.

We have failed because from the very outset we had no chance of success.

No one was ever charged in relation to the triple homicide.

But Brisbane-based crime historian Stephanie Bennett believes she has solved the state's oldest and one of its most brutal murder mysteries.

Ms Bennett has spent her retirement years poring over historical records in the Queensland State Archives and digging through prison records and believes she has uncovered the person responsible for the horrific crime.

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"There is absolutely no doubt whatsoever in my mind that the person responsible for this was a man by the name of John Joseph Quinn," she said.

"I started investigating the names of criminals in the Gatton area, people with police records, and the name Quinn kept coming up.

"The Sydney police, who were much better equipped to solve crimes than Queensland police were at that particular time, were convinced the place to look for the murderer was in and around Gatton."

Crime historian Stephanie Bennett. She believes she has worked out who was responsible of the triple murder on December 26, 1898 near Gatton. David Stuart

There is absolutely no doubt whatsoever in my mind that the person responsible for this was a man by the name of John Joseph Quinn.

Ms Bennett said over the course of investigating the triple murder she uncovered the fact Quinn had more than 300 known aliases.

But it was one particular physical attribute contained in Quinn's numerous police records that convinced her beyond doubt he was the killer.

"I can place him there, I can trace him and I can put him there," she said.

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"I always suspected him because of his record and the fact that he was changing his name the whole time.

"One of the main reasons I can trace him is because he was shot between the legs at one stage and the police description of scarring in that area, it did not matter what his name was, that physical description would never go away."

Ms Bennett said she believed Quinn, along with his brother Martin and an associate Thomas Day, plotted the murder from inside Boggo Road Gaol.

Gatton murder scene with police trackers at work, alongside Constable Murphy of Brisbane in the wattle scrub covered paddock belonging to Frank Moran. The Sulky belonging to the Murphy's siblings (middle of the image) was part of the Police Museum collection but sadly it disappeared sometime after 1938. Queensland Police Museum

One of the main reasons I can trace him is because he was shot between the legs at one stage and the police description of scarring in that area, it did not matter what his name was, that physical description would never go away.

"The three of them were inside Boggo Road Gaol together in early December 1898 and they planned it there," she said.

"They decided they were going to murder Michael at Christmas time and they worked out this business about the dance and that he would be coming back along the road at a certain time.

"I do not think the girls were part of the plan, though."

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Ms Bennett said the motive for the murder was because Michael Murphy had recognised Quinn during a trip to Longreach where he was moonlighting as a barber, exposing his criminal past in the process.

"Quinn swore in prison to another inmate that he would murder Michael Murphy because Michael had him imprisoned in Longreach," she said.

"Michael was in the mounted infantry and they were in camp at Longreach and Michael recognised Quinn, who was using a different alias from Gatton.

The area in which the Gatton murders took place. Queensland Police Museum

I do not think the girls were part of the plan ...

"Quinn was acting as the local barber but he was also holding union meetings inside the shop which was illegal at the time.

"Murphy reported him to the police and Quinn was jailed, and while he was in jail it stopped other plans Quinn and others had been working on."

The initial investigation was botched from the beginning, with Brisbane police not learning of the brutal triple murder straight away due to a number of communication breakdowns because of a reliance on telegrams.

Records contained in the Queensland Police Museum revealed the crime scene was not secured and a number of people passed through the area, possibly destroying valuable clues in the process.

The bodies were also moved before crime scene photos were taken.

All three bodies were strangely placed on a blanket in a way that formed a triangle and their legs placed in a way in which all their feet pointed west.

Nora, Ellen and Michael Murphy Murders: Nora, Ellen and Michael Murphy were murdered on December 26, 1898 near Gatton. Their murder is the state's oldest unsolved crimes. Picture: Queensland Police Museum Photo Contributed Queensland Police Museum

They decided they were going to murder Michael at Christmas time and they worked out this business about the dance and that he would be coming back along the road at a certain time.

This killer's signature has never been repeated since.

Queensland Police Inspector Frederick C. Urquhart, who headed up the investigation, said in his summary of the case: "We have failed because from the very outset we had no chance of success."

Urquhart went on to become Queensland's fourth police commissioner between 1917 and 1921.

The Murphy siblings are buried in the Gatton cemetery and Quinn is buried in an unmarked grave at Toowong cemetery.