David Eastman after his arrest in 1992.

David Eastman after his arrest in 1992. Photo: Graham Tidy

It is a matter for the ACT Director of Public Prosecutions, not the Supreme Court, whether there will be a retrial of David Eastman for the murder of Colin Winchester. But it is almost impossible that it could happen without a complete reinvestigation, by fresh detectives, and even then, there are major problems with witnesses, evidence and a cloud of prejudice against Eastman, some bits as little as a day old.

The Supreme Court has quashed the verdict, which means Eastman is again in the position of an ordinary accused person, entitled to be regarded as innocent until he is proven guilty. The finding of guilt has been removed. The court agreed with findings by Justice Brian Martin, who conducted an inquiry into Eastman's conviction 19 years ago, that there were fundamental flaws in the way the case was presented, which meant that Eastman was denied a fair chance of being acquitted. The court also adopted findings that vital forensic evidence was entirely unreliable, and joined in criticism of the Australian Federal Police for failing to investigate a recent tip (from the Victoria Police) that strengthened suspicions of organised crime involvement in the murder.

The DPP argued the court should either reject Martin's findings, or that it should hold that even with the flaws, the case against Eastman was so strong that there was no practical doubt as to his guilt. The court rejected both arguments but, in effect, put a challenge to the DPP: if the case against Eastman is so overwhelming even after discounting the discredited evidence, you should file a fresh indictment and he can face another trial.

A number of important witnesses have died in the 25 years since the murder, and 19 years since the trial. There will be problems with the memory of others, and it should by now be quite clear that a good deal of evidence that went unchallenged at the first trial will now be closely cross-examined. All police witnesses have now retired, and the conduct or reliability of a number were severely criticised by Martin in his report. Some of the criticisms will have the effect of weakening the strength of evidence presented; in other cases, it will seriously damage the reputation, and thus reliability, of some of the witnesses.

The biggest problem will be with forensic evidence, and with serious disturbance to the continuity of exhibits. The primary forensic witness, Robert Barnes, has been comprehensively discredited, but in any event he is dying and highly unlikely to be available at trial, even if he were willing. Amazingly, he was allowed to take most of the scientific material home with him after being sacked, for professional misconduct, by the Victoria Police Forensic Unit. He stored it in his garage, along with souvenirs of other cases. Most, but not all of it, was retrieved by police using a search warrant, but it is likely there would be a strong challenge to its admissibility, given the possibilities of tampering, confusion and identification.

Consideration of whether the case can be presented again will also underline the fact that the AFP has self-consciously never conducted any sort of internal review, second look or cold-case re-examination of its material in the face of major advances in forensic science over the past 20 years, or any fresh information or material that has emerged. That closed-mind lack of basic professionalism has been often criticised but will now come under the sharp spotlight.

New investigators put on the job would be starting again, and it is doubtful they will want assistance from the first team, whose approach and integrity has come under criticism. There is a wealth of documentary material, including witness statements, running sheets and incident reports: the AFP alone has more than 40,000 documents, apart from inquest, court and inquiry transcripts. But it is now evident there are many significant gaps requiring to be filled - if they can be after the lapse of time.

It would probably take at least two years before there was a brief to present to the DPP, and further time while the brief was examined by independent and previously uninvolved counsel. No doubt, police expect that during this period Eastman will be responsible for some indiscretion that will make their job more easy, but it seems certain the strategy of raising a case by its own bootstraps by any harassment of Eastman, in a manner venturing into impropriety, has had its day.

Eastman, 69, wants a quiet life and, probably, compensation, but is sensible enough not to rise to the bait.

One tactical advantage for police, prosecutors and public officials is that the delay before the DPP inevitably but regretfully decides that a re-prosecution is impossible if it can hold off talk about the need for a comprehensive inquiry into police mismanagement of the case, the use of fundamentally flawed forensic evidence, and failures to supply information which meant that Eastman was denied a fair trial. That's quite apart from refusing to consider the question of compensation until all the new events are over, perhaps in four years' time. No doubt by then a few of those with questions to answer will have departed from the scene, leaving the conundrums for others to solve.