The clue that was to link all the crimes was found easily enough at the first crime scene. At the cemetery where the first killings occurred, police found eight .22 –calibre shell casings by the car.
But with six years gap between the first and second double murders, no link was made between the cases and the similar bullet casings.
When the connection was made with the third double murder, ballistics showed that the same distinctive copper-jacketed bullets, manufactured in Australia in the 1950s, were used in both cases and came from the same box of 50 Winchester bullets. And it was the same .22-calibre Beretta automatic pistol had been used in the second killings. But the weapon has never been recovered.
The investigation was hampered by the fact that more than one person confessed to the killings when they were in fact innocent. Precious time was wasted on dead ends in a investigation that had very few leads due partly to an almost complete lack of witnesses to the killings.
After the last killing in 1985, over a hundred thousand people were questioned over the next eight years. By 1991, the investigation has started to focus on just one man.