The killing bore all of the signs of a professional hit. Winchester had stopped his car in the driveway of his next-door neighbour. He had removed the key from the ignition. His car window was open, and he was opening the door, at the same time, apparently, picking up a box of .22 ammunition sitting on the passenger seat. The ammunition had been picked up on his visit to his brother, because they had been planning a hunting trip to western NSW.

The assassin, it seems, had been hiding in a bush behind the car. He walked alongside the car towards the front, and, as Winchester shifted his body to get out, shot him through the head, from behind the right ear. Winchester slumped forward across the car's steering wheel. Within seconds, the man fired again, the bullet going through Winchester's right temple.

Then the killer walked away. He may have climbed into a car in the street, perhaps driven by someone else, or in a nearby street. There was a nearby laneway he may have used to walk from the immediate vicinity. He was carrying his weapon, which has never been found. No one saw him, or the weapon, although one neighbour heard the rumble of a V8 motor shortly after noises they thought to have been shots. (A Calabrian suspect, as it happens with an alibi provided by another suspect, was stopped the next day in a V8.)

In part because of inexperience, foolishness and incompetence, and in part because of the first thing police had thought when they arrived, the crime scene was a mess.

Senior detectives, and even the coroner, a big burly man, within a few hours trampled most of the ground and lawn around the car. The two most senior detectives there, Ric Ninness and Lloyd Worthy, supervised operations from alongside the car, about where the assassin would have fired. They called for lights and facilities to illuminate the scene, but from the water police, not the scientific squad. When scene of crime officers arrived, they had trouble getting scores of police, some merely gawking, to stop contaminating the scene, but were ignored or rudely dealt with, including with a statement that the men knew how murders were investigated. A senior officer was said to have said "But he's our mate''. It was hours before the scene of crime men could secure the scene.

Several cops searched the body. Another removed Winchester's car keys and went back, alone, to search Winchester's office at ACT Police headquarters. This man was, subsequently and briefly, himself to be a suspect in the case, a problem compounded by this solo initiative. Although uniformed police began securing the immediate area quickly, it was hours, and much too late, before detectives thought of doing anything about traffic going out of the city. By then the murderer could have driven to Sydney.

It was recognised that top forensic assistance, beyond the resources of the ACT would be needed. The man the top AFP forensic man wanted, from the Victoria Police forensic laboratory, was not available, and the man sent instead was explicitly one that the top man did not want. When this man arrived, flown up in a special aircraft, he seemed to assume that he was in charge, but hardly impressed. One of the first things he did, ungloved, was to put his hand, and fingerprints, on the roof above the driver's side door. This was to be the expert whose findings about the case have now been almost completely discredited – in part for breaking all of the rules about the collection and examination of forensic evidence.

Discussing the events in the days immediately after the shooting, most detectives, and most of their superiors, were certain that it had been a professional hit. The coolness and audacity of the murder and the escape suggested an experienced operator – a professional. "Mafia" specialists from Italy declared it bore all the hallmarks of a Mafia hit, and were soon reporting on suspicious recent movements to Australia by Italian associates of some of the leading Australian 'Ndrangheta families. The weapon originally thought to have been used – a .22 pistol – was said to be a characteristic weapon of hitmen. But it was the manner of the ambush and the shooting – and the fact that it embraced the so-called one-two "double tap", regarded as the hallmark of the trained assassin – was most often mentioned by all of the experienced observers. Spies, special forces troops, even police marksmen are trained in the double tap as the most effective manner of killing. It is not a characteristic of the opportunist murderer, even in cultures, such as the United States, where many are familar with guns.

A few hours after the shooting, ACT scientific squad investigators found two .22 cartridges trampled into the grass and mud near the place the murderer would have stood. These would have been found more quickly had not an array of ACT detectives, mostly old mates of Winchester's from his days in the ACT Police force, not gathered around the car to discuss what to do, to emote and to exchange ideas.

It was able to be shown, in due course, that these cartridges had been fired by a Ruger rifle. Some smart police work, by AFP forensic squad members in Canberra, was able to demonstrate that they had been fired by a particular rifle, sold recently by a Queanbeyan gun dealer. (There were spent cartridges known to be from the gun against which the cartridges at the scene could be compared.) But no one has ever established that the bullets that killed Winchester had been in these cartridges, or fired by that gun. Indeed, specialists in criminal hits and in organised crime warned investigators early on that hitmen often collected spent shells and left others lying around deliberately so as to hamper inquiries.

Two flattened .22 hollow-point bullets were lodged in Winchester's skull. They were not positively linked to the cartridge cases, or to a Ruger rifle. Nor did extensive forensic examination take any account of the fact that Winchester, a keen sporting shooter, was known to have had guns, ammunition and reloading equipment in his car before the assassination. Indeed, examination of the Winchester car did not last long; soon after it was professionally cleaned and disposed of at a police car auction.

One thought, apart from a professional hit, hit the ACT detectives about midnight, about 2½ hours after the crime. There was an ex-detective who had fallen out personally and professionally with many of his own colleagues and friends, and whose life had descended into alcoholism and bad family violence. He had been telling embarrassing tales about the formerly tight-knit detectives. Did he have a grudge big enough to have killed Winchester? Detectives were despatched to find out. But the man (who is now dead) had a cast-iron alibi, even if, over subsequent years, he and a number of others were to tell lurid tales about old colleagues, though not Winchester.

As news of the assassination spread upwards on the evening of January 10, senior police and politicians also assumed an organised crime involvement, with most of the focus being on the 'Ndrangheta. This Mafia or Camorra-style group was composed of people of Calabrian origin, active in rackets around south-eastern and northern Australia since the late 1940s. From the 1970s, some had had been involved in big drug crops, first around Griffith and the Riverina, later in northern NSW, in South Australia and the Northern Territory. They were members of big extended families and some of the surnames – Trimbole, Barbaro, and Sergi, for example – had became familiar in public discussions of organised crime, even as it should be remembered that hundreds of people with such surnames were law-abiding citizens. Cash from drug crops led to unexplained wealth in Griffith, Belconnen, Queanbeyan and Adelaide. Strong public suspicions about the corruption of police, particularly around Griffith, NSW, had led to several royal commissioins into organised crime, and to the murder of Mackay, a local citizen making a loud fuss, not least at evidence that local police had been neutralised. It was thought by organised crime intelligence operators, that there were between 60 and 70 initiated members of 'Ndrangheta (of perhaps 3000 people of Calabrian origin) living in the Canberra-Queanbeyan area.

The overwhelming proportion of Calabrians were hard-working and law-abiding, but as drugs became a problem in the ACT from the early 1970s, the sudden explosion of wealth of some families, as well as some association of players with political and criminal figures became obvious to local detectives.

As Winchester ascended the hierarchy he was drawn into national police operations, most of which were focused, one way or another, on drugs, drug importation and exports, and the investigation of organised criminals, most of whose income was based on drugs. 'Ndrangheta was a constantly recurring feature with cannabis, and Winchester, himself, was the author of some intelligence appreciations.

So far as police corruption was concerned, the AFP was also regarded as relatively clean – certainly a good deal more than the NSW Police, under whose eye most of the drugs were being cultivated and sold, and some of whom were seen, from the mid-1970s, to have become too close to many of the big players.

It soon became known that Winchester had supervised a number of AFP operations, including a major sting on significant 'Ndrangheta figures. He developed a relationship with Giuseppe Verduci, and, through Verducci, met a number of prominent drug lords interested in growing crops around Bungendore. Verducci was a slippery operator who played on both sides of the tracks. Winchester became involved in a controlled AFP-NSW Police operation in which he gave the impression that he was open to bribery. He was in due course approached to look the other way as a crop was sown. But he had not been turned. He had documented his activities, his conversations had been recorded, and the money placed in police safes.

In due course, Winchester handed over the practical running of the operation to other AFP detectives, but he retained ultimate control over the sting. Though high farce at time compromised operations, (including a rip-off of one crop, probably by corrupt NSW police) the task force finally sprang their trap, and 11 were arrested. They were less than amused, considering that they had arranged for and paid for their protection. Later, drug intelligence information suggested that the drug lords realised Verduci's treachery, and that a terrified Verduci, summoned to Adelaide for a 'Ndrangheta council of war, changed sides. He seemed to do this again several times more in the aftermath of Winchester's death.

At the time Winchester was shot, committal proceedings at Queanbeyan were less than a month away. Winchester was not scheduled to give evidence for the prosecution, but the defence had planned to call him in a claim of entrapment. In the event, the murder of Winchester caused the prosecutions to collapse, with Verduci claiming to be too frightened to give evidence.

Top cops, politicians and detectives thought Winchester could have been killed either to shut him up, or perhaps as a lesson to "other traitors". Indeed, a key phrase heard early in the affair was a recording in which an organised crime figure said that "a traitor is for the bullet".

The Australian Bureau of Criminal Intelligence concluded, on the basis of what it knew in 1990, that Winchester had been killed because of his involvement with the so-called Bungendore 11 at the orders of the Sergi branch of 'Ndrangheta. The Sergi family was the one "credited" with the death of Donald Mackay, as well as 23 other killings, mostly of its own. The report said that murder was being "utilised by the group as a disciplinary and defensive strategy to ensure the longevity and prosperity of the group”.

Shortly after the Winchester murder, a former principale of a Canberra 'Ndrangheta family, Pasquale Barbaro, was wounded at his home in Brisbane – shot in the shoulders by a shotgun loaded with light shot. Barbaro had fallen out with two of his brothers who were members of the Bungendore 11, because he had left his wife and gone to Brisbane with a new Filipina bride. Some thought the use of light shot amounted to an intended severe warning, rather than a murder attempt.

In any event, Barbaro was sufficiently infuriated that he approached the National Crime Authority in Brisbane, asking to be put into witness protection, and offering information on the Winchester murder. He made it clear that he wanted, ultimately, to claim the $250,000 police reward on offer, and his proffer was Winchester had been killed by members of his family. NCA officers said they would have to take time to consider his offer and make arrangements. Alas, before the NCA came back with an answer and received any details, another intruder arrived at the still unprotected Barbaro home. Barbaro was stabbed and shot by an Italian man aged between 25 and 30, who has never been found.

Detectives in the state and national criminal intelligence fields had a good deal of intelligence showing unusual activity among the crime families in the period immediately before and after the murder. Some was garnered by legal bugging and telephone taps (under warrant); a good deal more came from unauthorised buggings, informants and undercover agents. Much of this evidence would never have been admissible in a court; it had been gathered for intelligence so as to guide investigations, rather than as evidence in itself. To the locally gathered information came intelligence from Mafia and 'Ndrangheta specialists in Italy, including of suspicious flights in and out of Australia at the time of the case. A senior Italian magistrate specialising the the 'Ndrangheta, and since assassinated, was certain it was a drug family hit and told the AFP so.

There were any number of permutations of the Calabrian hitman theories, including ones which put the focus on various present or former NSW Police and their believed involvement with drugs and organised crime, and even some suggestions that some AFP officers had become corrupted by the easy money of the drug trade.

Even now, most of the intelligence gathered, and the reports which were based upon it, are subject to strict suppression orders, with police insisting that informants could still be killed if it became public. I first saw most of the suppressed material (copies of which I retain, if in a secure place) 20 years ago, and remain surprised that the public is not allowed to know how strongly the investigators who prepared the reports believed in an organised crime connection.

Those pursuing the professional hitman theory were quite convinced that continuing investigations, with more resources, would bear fruit. But while there was a rich web of circumstance and coincidence, and, not surprisingly, a lot of very suspicious activity, the investigators focused on this side of the case were failing to find a smoking gun -- clear evidence pointing unequivocally to someone's guilt. The brief wanted more work, more time, and more investigation. It never got it. A rival team believed it was working on a more workable theory, and pushing to have the national investigation closed down.

In this article I have spoken of the "second thing" that police thought. The first thing that they thought, as detectives usually think, was that if Winchester had been murdered, it was probably by his wife. There was no evidence pointing in this direction, simply that cold statistic that says that in most homicides (including police homicides) a spouse is responsible. The AFP, like most police forces, has long had a rate of spouse homicide, marital violence, suicide and bitter separation much higher than most other occupations, and the stresses and strains of police life make many police especially compassionate towards the victims, a reason some detectives present would have fuzzed some of the material had there been any evidence pointing to a spouse murder. Indeed, there was a rifle in the house. But this professional instinct to check a possibility found no evidence whatever pointing to a domestic murder, leading to a quick and proper change of focus.