It has been more than 20 years since Detective Sergeant Geoffrey Bowen was killed by a mail bomb while investigating organised crime at the National Crime Authority building in Adelaide.
But South Australia Police say they believe they are finally closing in on his killer.
Detective Superintendent Des Bray is the head of Major Crimes Investigation in South Australia.
“The investigation is going extremely well,” he said. “We are probably in a much better place than what we thought we would be by now.”
Task Force Cornus was set up last year to look into the cold case.
“We had a team of investigators working for seven or eight months in advance of an investigation starting,” said Detective Bray.
“They were doing it full time, and they reviewed every document, every piece of evidence or item collected during the course of the investigation.”
Mail bomb explosion
In 1994, Detective Sergeant Geoffrey Bowen, a 36-year-old police officer from Western Australia, was working with the National Crime Authority in Adelaide.
On the morning of March 2, he had gone to the mail room on the 12th floor of the building to retrieve a parcel.
According to a colleague who was with him at the time, Peter Wallis, the parcel was inspected with a metal detector and deemed to be safe.
But when Geoffrey Bowen ripped open the Yellow Express post envelope, its contents exploded, killing him.
Peter Wallis was badly injured, but survived. Four other employees were taken to hospital.
Firefighters described the aftermath as “an horrific scene to walk into”.
The blast was so destructive it shattered a window, sending glass scattering onto busy Waymouth Street in Adelaide’s central business district.
Crime scene photos released by South Australia Police show blackened office equipment, a computer and a fire hydrant strewn across the room in the aftermath of the incident.
Parts of the envelope containing the bomb were salvaged and retained as evidence.
The scene of the bombing. Source: SAPOL
Crucial new evidence
The review has uncovered new details about the case, with 65 items being sent to the Netherlands to be tested using the latest DNA technology.
Additional fingerprints and partial DNA profiles have been recovered, and police now know how the bomb was constructed.
Police are following several new lines of inquiry, and now believe several men and a woman were involved both before and after the bombing.
They also know that someone tried to obtain the home address of Geoffrey Bowen prior to his death.
A week after the bombing, an Adelaide man was arrested and charged with murder and attempted murder.
But charges against him were dropped months later by the then-Director of Public Prosecutions, who cited a lack of evidence.
Links to Calabrian mafia
The National Crime Authority was set up in 1984 with a mandate to investigate organised crime.
At the time of his death, Detective Sergeant Bowen was working on Operation Cerberus, which looked into Italian organised crime in Australia.
Detective Superintendent Bray said police were now appealing directly to Australia's Italian communities for any information about the case.
“A number of the people that we believe are involved in the bombing are of Italian background, and we believe there will also be witnesses and people with information within the Italian community.
“I think nationally there are people who are interested in what’s going on here, and also back in Italy.”
Last month, the South Australia Police released updates on the case and appealed for information with press releases written in Italian.
The scene of the bombing in 1994. Source: SAPOL
Clive Small, former NSW Police Assistant Commissioner-turned author, said it was important to appeal to Italian speakers.
He said he believed those responsible for Geoffrey Bowen's death might be among those the detective sergeant was investigating.
“That again raises the spectre of the Calabrian mafia,” he said.
“The Calabrian mafia is, in fact, Australia’s longest continually running and growing organised crime syndicate.”
Mr Small, who has written a book about the Calabrian mafia's workings in Australia, said Australian police had known for decades that organised crime groups with links to Italy had operated across the country.
"For 16 years, they have either remained silent on this matter, or issued denials, and it was only in 2011 that for reasons best known to [the] Australian Crime Commission as it was then named, came out and said 'yes, there is a Calabrian mafia in Australia'.
"For 16 years, they lived in denial. That should be explained to the Australian public. We deserve an explanation for that."
Detective Superintendent Des Bray would not comment on whether the Calabrian mafia – or 'Ndrangheta as it is also known – is part of the inquiry into Geoffrey Bowen's death.
“I’m not going to speculate on that,” he said. “That is for others to speak about.”
South Australian investigators are still hoping to speak with people who know more about the 1994 killing of Detective Sergeant Geoffrey Bowen.
There is a $1 million reward for anyone with information that leads to a conviction, and immunity for those not directly involved in the murder.
Police are asking anyone with possible information about the 1994 bombing to contact Crime Stoppers on 1800 333 000.
Anyone calling Crime Stoppers with information can be transferred to a Task Force Cornus investigator, or they can contact task force investigators directly by emailing:
