It was then that he hinted to police that he was willing to give them information about Walsh Street.

He gave a statement, the first of many, on October 21 and Jedd Houghton, a family friend, was one of the first people he implicated.

Within two weeks of the killings, the Victorian government quietly passed legislation allowing phone-tapping by state police.

Previously, they had to work with federal police who had this power if they wanted to use their recordings as evidence.

Five months passed before the legislation was made public.

On October 24, 1988, police took Jason Ryan on a trip to the country (Bright, north-east Victoria).

Ty/Eyre Task Force head, Det John Noonan escorted Ryan to the small town and there the accusations against the four charged, as well as others involved, were born.

"There wasn't many barbeques, I can tell you that," Ryan later told journalist Paul Anderson of his trip, "they tried to put the wind up me."

"I told them bits and pieces and told them bullshit because I didn't trust them," Ryan says.

"They threatened to throw me back on the street and tell certain people that I said this and that. Because I had been gone for a certain amount of time (on the country trip), maybe people would have believed it. I was only seventeen and confused. I didn't know what was going on. In the end I got to meet John Noonan. He said to me, 'Listen, what you're telling us is bullshit. Some of it's true and some of it's not.' He said them other police were not having anymore dealings with me. It was just him and me from there on."

Ryan speaks highly of Noonan saying he slowly grew to trust him and eventually told him the truth.

"I was still hesitant and told him a couple of lies at first," Ryan claims.

"He kept coming back to me and saying, 'This just doesn't gel.' I got to trust him and eventually told him the truth."

Ryan gave Noonan up to half a dozen accounts of the events on the night of the double shooting, including re-enactments at the death scene.

Flemington armed robber Gary Abdallah became a suspect on the evidence of Jason Ryan put forward on October 27.

Ryan claimed that Abdallah's part in the killings was to provide and drive the getaway car. 

For two months Gary Abdallah eluded the police.

Raids were made on all known associates including his girlfriends family and the family of Jedd Houghton.

News filtered back that police intended to kill him if they got to him first.

Ryan gave crucial, but ever changing evidence in the Walsh Street trials.

He was placed under witness protection.

Noonan told Paul Anderson, a journalist with the Herald Sun, he understood Ryan's reasons for telling several different versions before he settled on his final statement. 

"By telling five or six stories meant he was a liar at first, but you have to understand he didn't trust police," Noonan said.

"He trusted the police no more than he trusted his family and their criminal associates. Police used to actively assist Dennis in his activities and Jason was privy to that. He was worried his information would get back to the family and there were times when he gave us false information purely and simply to see what was going to happen to it." 

In earlier versions Ryan even placed himself in Walsh Street, saying he broke into the Commodore which was used as 'bait'.

Having admitted to aiding and abetting in the shootings, he was the first to be charged over the murders.

On the last day of October - Melbourne Cup Day eve - a Supreme Court judge acting after hours bailed him into the care of his police minders.

Ryan would implicate five men he claimed set off with shotguns for Walsh Street in the early morning of October 12.

He listed the party of killers as being Jedd Houghton, Victor George Peirce, 31, Peter David McEvoy, 34, of Elsternwick and Trevor Pettingill of Richmond as well as Farrell.

"On Melbourne Cup Day I rang me mum and she said, 'Look, the coppers have just been here and taken some of your clothes," Farrell later said.

"I had newspaper clippings over Graeme (Jensen) and they took them too.

I rang St Kilda Road and Noonan got on the phone and I asked, 'What's going on?'

He said, 'We want to see you again and show you some photographs.'"

The two met on neutral ground in Clarendon street, South Melbourne.

Farrell said Noonan told him it would not look good being seen speaking openly with police, so he hopped into the detective's unmarked car.

Instead of showing him photos, Noonan drove Farrell back to the Homicide office.

Farrell he said the TyEyre taskforce detectives were bluffing him as, after interviewing him, they drove him to the watchhouse where he would be charged and remanded in custody.

Farrell sat in jail on remand for two and a half years before he came to trial.

Detectives saw Farrell, 20 at the time of his arrest, as the weak link in the chain.

If they could break him and get a confession, they believed they would be well on their way to exacting justice.

By November 1988, at least a dozen people were under 24-hour surveillance.

All of the murder suspects had long histories of criminal activity.

Two weeks after Farrell was arrested, Jedd Houghton was killed by police.

On November 17, 1988, Houghton, then 23, was shot dead by two members of the Special Operations Group at a Bendigo caravan park.

Police wanted to arrest him for questioning and knowing they were searching for him, Houghton had been hiding out in a cabin with his girlfriend.

Farrell later gave his version of the events of the night of the Walsh Street shootings to Paul Anderson.

"We were at a pub in Carlton and ended up back at Jason's that night," Farrell claimed.

"Jason stayed there. His mum was there. I can't remember seeing if McEvoy was there or not but I do remember seeing him there that night. At the end of the night me and (mate) Manny Alexandris were downstairs in the lounge room. I fell asleep on one end of the couch and he fell asleep on the other."

In a series of video interviews in 1989 that detailed a decade of crime, including several murders by her brother-in-law Dennis Allen, Wendy Peirce had examined bank security pictures and identified those in them.

Wendy said she recognised her husband, Jensen, Houghton and McEvoy by their clothes, shoes, features, and stance.

She informed police that her husband told her when he was planning a robbery; she knew when he was conducting surveillance on targets and that she knew when he completed a job because he came home with money.

Wendy gave much evidence at the committal hearing but days before the 1991 trial of the four men, she decided not to testify against Peirce, blowing a substantial hole in the prosecution case.

She withdrew a statement that on the night of the police killings Victor had told her, "I'm going to get the Jacks (police) that knocked Graeme (Jensen).

She was later sentenced to 18 months' jail with a minimum of nine months for perjury.

Ryan stuck to his guns and placed his implicated five at the flat in Gordon Grove, off Walsh Street in South Yarra, referred to otherwise as murder headquarters.

He detailed the alleged conversations and motives. The court was told the murders were revenge killings - a two-cops-for-one-crook kill bid as payback for Jensen.

The defence lawyers laid assault on Ryan's credibility. David Ross, QC, for Farrell, painted the picture of Ryan's upbringing to question his honesty and veracity of his evidence.

During cross-examination ,Ryan denied he had been a "messenger" for his Uncle Dennis (Allen) but agreed he knew of several murders his uncle had committed.

Ross put to Ryan that he handed Dennis a loaded pistol that was then "emptied into the head of Wayne Stanhope". Ryan refused to answer the question for fear of incriminating himself. Ross the alleged that on Dennis Allen's birthday in 1985 the drug kingpin killed Anton Kenny.

In his final submission, Ross described Ryan as a cunning "little street-wise urchin". "The lies he tells about Anthony Farrell and others are indiscriminate and without reason," he told the court. "We (the entire defence panel) suggest to your worship that you have never come such a lying person as Jason Ryan."

After hearing the prosecution case, ending on February 22, 1990, Magistrate Hugh Adams deemed there was insufficient evidence for the three to stand trial.

Adams said there was "no doubt" in his mind that Jedd Houghton played an "active part" in the slayings. He also said there was insufficient evidence for him to direct Trevor Pettingill be charged, and suggested the Director of Public Prosecutions may wish to "address his mind to the matter".

All three defendants maintained their "not guilty" pleas. Peirce's alibi had him with wife Wendy and their children at the Tullamarine motel.

McEvoy claimed he was sleeping in his room at Ryan's mother's Brunswick flat.

Farrell maintained he was in a drug-induced sleep on the couch at the very same flat.

On the order of the Office of the Director of Public Prosecutions, Pettingill was charged in July 1990.

Without a proper committal hearing, he was presented to the Supreme Court to stand trial with the three others. His plea was also "not guilty", his alibi being that he was in a sedative-induced sleep at the time of the shootings.

Weeks before the trial, during a voire dire, Wendy, reunited with her husband - a man who once shot bullets at her feet and broke a finger as a punishment - recanted and turned hostile witness.

She claimed investigators, or "gangsters with badges" as she called them, had forced her to tell lies about her husband's involvement.

That despite her having told the Magistrates' Court: "Rumours that I am being hypnotised, tortured and bashed are not true. I am here of my own free will."

At trial in 1991, under the watchful eye of Justice Frank Vincent, Jason Ryan was left to bear the weight of the prosecution case on his shoulders.

He was now the Crown's star soloist. Nervous and intimidated, Ryan gave detailed evidence against the accused just as he had at his committal.

He told of the gathering at the Gordon Grove flat and how the five had argued over the shotguns before heading out. He said he stayed behind to guard the flat while the others set up a car as bait and shot the constables.

He said he heard shots before one of the accused returned with blood on his tracksuit pants. Ryan also said he was told that if he said anything about that fateful night he would share the same fate as the shot policemen.

The defence lawyers hammered Ryan's credibility during cross-examination. If his testimony proved doubtful, the jury would have a difficult task settling on a guilty verdict.

Ian Hayden, for Farrell, described Ryan as a burglar, liar, thief and cheat. Geoff Flatman, for Peirce, played the jury several of Ryan's re-enactments in which the young Crown witness continually changed his story. "He ingenious at picking up snippets of information and using them," Flatman told the jury. "It's kids playing silly games. He's playing God." Chris Dane, QC, for Pettingill, said Ryan has "verballed" his client and he asked the jury to do with the evidence "what the jury in the Birmingham Six case should have done with the verbal confessions presented to them - treated t with the contempt it deserves".

Bob Vernon, for McEvoy, told the jury they were being asked to convict his client on "tainted, suspect and manipulated testimony" given by "court-room rehearsed witnesses, harassed and frightened witnesses and self-confessed liars".

"There are witnesses who have changed tack more times than a yacht in a twelve-metre yacht race," Vernon said.

"These witnesses have poisoned the well of justice. They said Adolf Hitler was the difficult son of a difficult mother, and one can but wonder if Jason Ryan is not the difficult son of a difficult mother."

Crown prosecutor James Morrisey, QC, conceded Ryan had a black background. "You are not going to get the Archbishop of Canterbury or Mother Teresa from within the group," he said.

Forensic evidence linking the four accused to the murder scene was next to nothing. Circumstantial evidence had linked the main murder weapon - the Japanese-made KTG shotgun - to an armed robbery crew allegedly including Houghton and Jensen. It is believed the bandit crew had used the gun during a series of hold-ups before the police murders.

The prosecution believed six people were involved in the ambush (including Jason Ryan and Jedd Houghton). 

But only two were needed to complete the killings and only two people were seen.

After more than six weeks at trial and six days of deliberation, the all male jury came back on March 26, 1991 and acquitted Farrell, Peirce, McEvoy and Pettingill.

Kath Pettingill was ecstatic.

Detectives who had sacrificed all investigation the case were shattered.

"The Walsh Street four have been acquitted. All units stay under control," was the D-24 broadcast to all police cars on the road.

Noonan said the result was one of disbelief and total disappointment.

He added that the jury had found the accused not guilty but had not found them innocent.

The acquitted immediately called for a Royal Commission into the investigation. Noonan welcomed the call, saying it would vindicate the police decision to charge them by revealing evidence inadmissible at trial.

When Paul Anderson spoke to Farrell in 1998, Farrell said the acquittal was the happiest day of his life. He said he still held fears for his safety having been branded forever by the police murder charges.

Peter McEvoy was later sentenced to seven years for armed robbery.

After his release he lived in northern Victoria before moving to New South Wales.

Victor Peirce spent several years in jail for drug trafficking and upon his release worked for Italian fruit marker identity Frank Benvenuto.

Benvenuto was murdered in 2000.

Peirce was shot dead in an execution-style killing in Bay Street, Port Melbourne on May 1, 2002.

His murder, during Melbourne's gangland war, remains unsolved but police belive slain hitman Andrew 'Benji' Veniamin to have been responsible for the deaths of both Benvenuto and Peirce.

Anthony Farrell, a heroin addict, has maintained he tried to leave his past behind and get on with a life not involving crime.

But he has been jailed twice for drug offences since the Walsh Street trial.

Jason Ryan remained under witness protection and moved interstate.

He has also had an on-going battle with heroin addiction and has been arrested and jailed several times.

Trevor Pettingill moved away from Melbourne to the family hideaway at Venus Bay after the acquittal.

Later that year he appeared in Heidelberg Magistrates' Court charged with aggravated burglary, theft and carrying a weapon.

The burglary, theft and weapons charges were adjourned along with dangerous and unlicensed driving charges to give Trevor a chance to beat his heroin addiction at Odyssey House.

In 1993, Pettingill was again in court, once on a charge of growing marijuana and, while on bail on that charge, with his mother and 10 others to face further drug charges.

Trevor was sentenced to a minimum 45 months jail when the case came to trial and the court was told of his 32 previous convictions.

In 2001 he was in court again charged with street offences after trying to help a man bailed up by railway inspectors.

He told a suspected fare-evader at North Melbourne station that all you had to do to do to ticket inspectors was "whack them one and walk away."

The magistrate fined Pettingill $500 and described him as a "devotee of democratic justice."