Dead men do tell tales . . .

On that ring was an RACV tag, which was used to identify a woman who was literally dragged into an armed robbery that ended with a murder. An injured gunman forced her out of her car so he could escape after fatally wounding a security guard in the Brunswick robbery.

It should not have been enough to identify her but the gang had contacts at the Motor Registration Branch and found out where she lived. When police raided the gang's Doncaster safe house they found a page ripped from the White Pages. On it was the woman's name and address.

The gang's plan was as simple as it was brutal. If they killed the only person who could identify them they would be in the clear.

Now 23 years ago this month, a change in the Evidence Act means that testimony from a notorious insider who has since died could be admitted in court and it is that twist that created fresh interest in the case.

Finally, it seems, dead men do tell tales.

For the armed robbery team responsible for some of Australia's biggest hold-ups, the Coles store in Brunswick was a lightweight job. The gang had a source inside Armaguard who, for 10 per cent of the takings, had provided information on six robberies totalling $500,000.

But this time the details were exaggerated. It was supposed to be an easy $200,000 but the July 11, 1988, job netted only $33,000 and went horribly wrong when security guard Dominik Hefti refused to surrender.

During a struggle, Hefti, 31, was shot in the chest and leg but returned fire, shooting one of the robbers through the hand. The injured gunman ran to the car park where he dragged a woman from her Nissan Pulsar in Barkly Square and drove off, leaving a trail of blood, while the other two escaped in their own getaway car.

Hefti died in the Royal Melbourne Hospital two days later.

From the moment members of the armed robbery squad arrived at the scene they nominated a prolific stick-up crew headed by career criminal Victor Peirce.

What they didn't know was there was a second gang led by the notorious Russell Cox that was pulling the armoured van jobs.

The armed robbery squad's flawed theory proved to be fatal when detectives shot and killed Peirce's close friend Graeme Jensen in a shopping strip in Narre Warren on October 11, 1988, while trying to arrest him over the Hefti murder. The following day two uniformed police, Constables Steven Tynan and Damian Eyre were ambushed and killed in Walsh Street, South Yarra, as a payback for the Jensen killing.

While the armed robbery squad was right to conclude the gang that killed Hefti were full-time bandits, they were wrong in deducing it was Peirce and Jensen.

It was only when blood taken from Jensen's body failed to match a sample of blood found at the Hefti crime scene that they found they had killed an innocent man.

It would be years before police would find the names of the real robbers. Then, using groundbreaking DNA technology, they established Dominik Hefti's killer was Santo Mercuri, a sausage maker turned gunman.

The initial break in the case came when police accidentally stumbled on Australia's most wanted man and arrested him after a shootout at Doncaster Shoppingtown.

Russell "Mad Dog" Cox was serving life for the attempted murder of a prison officer in an earlier escape when he broke out of the top-security Katingal division of Sydney's Long Bay Prison in 1977.

In his 11 years on the run Cox committed a series of armed robberies in Queensland (six between 1978 and 1983) and Victoria and was linked to three murders.

It ended on July 22, 1988, when the crew from an armoured van heading to Doncaster Shoppingtown radioed police to say they feared they were being followed. By luck an armed robbery squad team, headed by Paul "Fish" Mullett, was a few suburbs away and with the aid of every green light on the road, made the car park in minutes.

Soon three armed robbery crews, armed with handguns and pistol-grip shotguns, were prowling the shopping centre. And there wasn't even a sale on.

Detectives opened a Holden station wagon rear gate and found the prison library card of notorious gunman Raymond John Denning, who had escaped from Goulburn Prison in New South Wales just days before.

It was a stupid mistake from a smart crook. Denning was a cult hero among the anti-establishment intelligentsia in inner-suburban Sydney. Articulate and outspoken, Denning took on the prison system but he was not silly enough to take on the armed robbery squad.

When confronted on his return to the car, he retired from crime immediately. In fairness, armed robbery squad detective Ken Ashworth was standing on the bonnet of the vehicle brandishing a loaded shotgun at the time. Denning's options were simple: retirement or a 12-gauge redundancy package. (We have seen Ashworth brandishing a $20 note at the bar of the Police Club as last drinks were called and that was frightening enough. The vision still haunts us more than 20 years on.)

Cox took off in his yellow Ford Fairlane and headed for what he thought was the exit, chased by a large number of armed police. He waved a gun at his pursuers who opened fire in a scene reminiscent of The Blues Brothers until he crashed and was arrested.

As expected, he said nothing. But later Denning concluded the underworld code of silence was an outdated concept and decided to open up.

"He said they were following the van 'for fun' and had no intention of robbing it - at least not then," said one of the arresting detectives, Dave "Gull" Brodie.

Denning didn't want to spend the rest of his life in jail and made statements implicating others, including his mate Cox.

Months after the Shoppingtown arrest, Denning and Cox were in adjoining cells in Pentridge when Jensen was killed. According to Denning, Cox was delighted the wrong man was blamed for the Hefti murder and gloated that he was now in the clear. "Russell Cox told me that this murder and armed robbery committed on Dominik Hefti had been done so by himself with Sam Mercuri and a person named Mark Moran."

Mark Moran was a little-known gunman at the time. He would gain posthumous notoriety after he was murdered outside his Aberfeldie home in June 2000 as part of the underworld war.

Later Ashworth would re-investigate the Hefti murder and link Mercuri to the crime in the first Victorian case based on DNA.

Mercuri, 47, pleaded not guilty to murder and armed robbery but the forensic material was overwhelming. He was sentenced to 25 years with a minimum of 20. He died in jail in 2000.

Police were delighted when Denning changed sides. Others less so.

He received a shortened jail term in exchange for his co-operation but died in 1999 of a drug overdose that many still believe was a hotshot. He died only days before he was to give evidence against Cox in an armed robbery case and only weeks after Mercuri was arrested for the Hefti murder.

Most of the cases against Cox collapsed when Denning's did. He was released from a prison in 2004 and moved to a quiet Brisbane suburb with Helen Deane, who he married in jail.

Victorian detectives have looked at Cox over the Hefti murder, and the unsolved killing of standover man Brian Kane, who was shot dead in a Brunswick Hotel in November 1982.

The reason for the fresh interest is simple. If they can get Cox they can get his close mate the man they call "the Duke" who was part of the team who killed Kane.

And they want "the Duke" because he is the man said to have killed police informer Terence Hodson and his wife Christine in Kew in May 2004.

Police have been able to independently corroborate many of Denning's allegations but without a fresh witness they may still be on a road to nowhere.

Cox got away from police for 11 years while he was on the run. And now it looks as if he will get away with murder.

The real question is, will "the Duke"?