15m electrical cord, with a plug at one end and an extension cord socket on the other, was discarded at the Glenroy home, when Crawford left suddenly before he had a chance to cover up his evil crimes.
The cord was a crudely-built electrocution device he used to murder his family on July 1, 1970,— starting with his pregnant wife Therese, 35, and his oldest daughter Kathryn, 13, and son James, 8.
Running from the main cord were five small leads with alligator clips attached to them. When his family were asleep he clipped them to their ears and shocked them.
The children were attacked with a blunt instrument, their skulls fractured with what a pathologist believed was a hammer.
The youngest child, six-year-old Karen, was spared from the shock treatment, instead, killed with the hammer.
Once they were dead he wrapped them in blankets and placed a tarpaulin over them. In a sign he planned the crime to the last detail, he’d removed the seat in his Holden sedan so he could stack the bodies inside.
The next step in his plan was to make it appear his wife was the killer. He drove the car to the top of a cliff, hundreds of kilometres away — at Loch Ard Gorge, near Port Campbell — and rolled it over. But before he did so he placed a hose to the exhaust and pushed it through the driver’s side window.
An inquest into their deaths later heard that was possibly why his wife was never attacked with the hammer — so when police finally found the bodies it would appear she beat the children to death before driving over the edge.
The car on the rocks
The plan was ultimately foiled when the car landed on a rocky ledge almost 20m below. It was discovered the next day.
A police officer went to Crawford’s door after the car was traced to him.
But they hadn’t been able to get to the car, so were unaware of the bodies inside it, wrapped in bed sheets.
Crawford didn’t answer the door when the police knocked. But it is believed that was at this moment he decided to quickly leave.
There was evidence he had tried to clean his blood-splattered home.
He’d tried to clean the carpets with detergent but the blood stains were still visible.
Crawford became one of Australia’s most notorious and wanted suspects, but there have been few concrete leads. So far he still avoids capture.
The strongest lead related to sightings in Western Australia in 1994 which police believe were genuine.
A woman who knew Crawford well saw a man in a Bunbury hotel and was so convinced it was him she approached him and asked who he was.
He claimed he was a tourist from New Zealand.
Despite public appeals and a $100,000 reward, extensive searches never located the man.
In 2005 investigators believed they may have cracked the case when a body in a US morgue was identified as potentially being Crawford.
The mystery figure had gone to great lengths to conceal his true identity. He’d damaged his fingerprints and carried multiple false identity documents in at least four different names.
The possibility it could be Crawford was the strongest sign in almost four decades that the mass killer could finally have been tracked down.
But DNA testing revealed that the unidentified man was not him.
If he is still alive, Crawford would be 85 years old. During their last public appeal, police hinted at the frustration at not being able to bring such a vicious killer to justice.