In 2013 Iddles completed his report,codenamed Rainmaker,concluding:“I am unable to find any material or evidence which would show Roberts’ new account is contradicted in any way by evidence presented at the original Supreme Court trial.”

Iddles expressed an expert opinion. It was not evidence. When the report was made public,Iddles went further,saying:“On the basis of probability,he[Roberts] was not there.”

It created headlines and little else. To win a retrial,Roberts’ legal team had to produce new and compelling material denied to the original 2002 jury. Roberts could have given the account he gave Iddles at his original trial. Instead,he had denied everything.

It would have ended there,except that a copy of the original statement from one of the first police at the scene where Silk lay dead and Miller dying was unearthed - a statement hidden from the defence and the jury in the first trial.

An addition to a statement is common when filed as a supplementary document,giving the defence the chance to explore potential inconsistencies.

In this case,however,the original statement had been destroyed and a later one backdated to appear as if it was taken within hours of the shooting. It related to a key plank of the prosecution case:that Miller said there were two offenders,allegedly Debs and Roberts.

The fact that several original statements had been altered to back the “two offenders” call was the new and compelling evidence that made the Court of Appeal order a retrial.

The act of hiding the original statements was a spectacularly stupid attempt to produce a watertight case.

Any suggestion the statements were altered to falsely implicate Roberts is misguided,since Debs and Roberts did not become suspects until five months after the alterations were made. It was a tidy-up rather than a cover-up,yet still inexcusable. It was the subject of severe criticism from the Court of Appeal and the Independent Broad-based Anti-corruption Commission and is now being investigated by police to see if disciplinary charges should be laid.

If the Court of Appeal believed there was insufficient evidence to convict Roberts it could have ordered an acquittal. Instead,it found the prosecution case was strong,saying:“We accept that the consistent history of the manner in which the Hamada robberies were committed by Debs and the appellant[Roberts] raises a strong probability that (absent other evidence) if the Hyundai car was present at the Silky Emperor for the purposes of robbery,then both men were present.”

In this trial,the first responders were questioned on what they heard,what was recorded in their first statements and any contradictions in previous evidence.

Their evidence that Miller said two offenders was pivotal because two police who drove along Cochranes Road saw Silk and Miller near the Hyundai and only one other person standing at the driver’s door. The Crown claimed they didn’t see Roberts because he was slumping in the front passenger seat.

One witness who has since died said he drove past to see a police car and a second car parked in Cochranes Road with both the passenger and driver’s door of the second car wide open.

The prosecution claimed that if it was the Hyundai,two people had left the car to speak to police.

During the second trial,one first responder denied he could be mistaken about what he heard,saying those words were “going to haunt me until my death”.

One of the first police there was Cheltenham Constable Brad Gardner,who was on a routine 6pm to 2am patrol. The most junior officer at the scene,having only graduated the year before,he held Miller’s hand and cradled his head. He took notes at the time,which included what Miller said when asked for descriptions.

Prosecutor Ben Ihle,QC,asked:“And what was his response?”

Gardner:“Two,one on foot.”

Ihle:“What did you do with that information?”

Gardner:“I wrote it into my notebook.”

Gardner hopped into the ambulance to write down anything else Miller might say. He followed him all the way to the Monash Hospital operating theatre and waited outside until he was told Miller was dead.

Gardner has left policing and is now a truck driver.

The Court of Appeal had earlier made reference to Gardner’s recollections.

“He wrote ‘two,one on foot’. Gardner was a very deliberate and precise witness.” Three of Victoria’s most experienced judges clearly believed him.

Senior defence barrister David Hallowes,SC,repeatedly questioned the credibility of some of the first responders but accepted Gardner’s version from his notes taken at the time that Miller said “two,one on foot”. (Hallowes did however question whether it meant categorically that Miller was referring to two offenders.)

The reason for the retrial - whether Miller had referred to two people - was finally conceded.

While the retrial gave the defence the chance to examine the first responders on inconsistencies in statements,it gave the prosecution the chance to recalibrate.

As Roberts now admitted he was Debs’ partner in the 10 armed robberies,the prosecution argued the jury could reasonably conclude he was in Cochranes Road for the 11th.

And this time Debs would break his silence. His evidence was fascinating and horrible. He showed no remorse and discussed the ambush murder of two police as if checking off a shopping list.

His version was different to the prosecution’s,and he admitted to the defence he was a liar. He had a motive to give evidence:he hoped to be rewarded by being transferred from NSW’s Goulburn Prison back to Melbourne to be closer to his family.

But for all that he was unshakeable:Roberts was there and killed Silk.

Kaye warned the jury that as a convicted criminal,any evidence Debs gave should be treated with caution. Clearly the jury didn’t believe him.

Debs was a serial killer. His life sentence has saved lives.

For Roberts to stand any chance he had to jump into the witness box and open himself up to cross-examination - a high-risk,high-reward tactic. An accused usually stays silent,leaving it to the prosecution to prove its case beyond reasonable doubt.

Roberts was solid and articulate,giving his version of what happened that night - based on what he said Debs had told him.

Roberts said he spent the night at the Debs’ house. During the public campaign on behalf of Roberts,Nicole Debs said she would give evidence that she was with him that night,but come the trial she was not called.

Only Debs gave evidence that Roberts was at the house - but says they left together to go to the Silky Emperor.

In the first trial,the jury was told that Roberts was bugged bragging “I kill Ds”,a statement the prosecution alleged referred to killing police. This time the tape wasn’t played because it may have been “I’d kill Ds”,which could be interpreted as a macho boast.

In bugged conversations,when Debs spoke of the murders he spoke of more than one offender:“Those were the ones[Silk/Miller] that were sittin’ there,when we drove in just to quickly look[at the restaurant],they seen us so they drove behind us,and drove down the street to stop us,they stopped us. Then it’s not good … ’Cause we heard it on this,we heard it on that,they said ‘oh one is gone[Silk] we can’t find the other one[Miller]’. After we left they come[sic] in 30 or 40 seconds. Thirty or 40 seconds they were there,that means they had a few[police] cars in the area.”

The prosecution case was based on bugged conversations and forensic reconstructions,but there were no witnesses. The truth is only two people know what really happened. Debs,who is doomed by his own actions to die in jail,and Roberts,who is now a free man.