A jury whittled down to just nine members after two gruelling years at the final Hillsborough inquest concluded, among other significant findings, that the 96 victims had been killed unlawfully, and that the fans had not contributed to the disaster in any way.

"I had my head down over my notes writing in the way you are," Scraton said. "On my pad, you can still see the tears on my notes where the ink's run. It was emotional and it was incredible and it was completely, at that moment, it was not predicted.

"People say to me, 'Surely you must have known you were going to get that verdict'. No way, a jury is a jury is a jury. They'd had so much stuff thrown at them."

So had the survivors of Hillsborough, and the family members of the victims. They'd sat through a 27-year hell fighting for justice for their lost loved ones, justice for survivors and family members who had subsequently taken their own lives, and justice for those who had fought bravely but were no longer around when the final inquest took place.

Lifelong Liverpool fan Scraton, a Professor of Criminology at Queen's University in Belfast and a visiting Professor at UNSW, didn't attend the fateful FA Cup semi-final at Hillsborough on April 15 in 1989.

He was at home writing a book about prisons as the worst sporting disaster in British history unfolded, moments after kick-off during the game between Liverpool and Nottingham Forest. Scores of Liverpool fans who had been crammed into two enclosed terraced pens at the home of Sheffield Wednesday were crushed to death. A lack of turnstiles at one end of Hillsborough had led to massive overcrowding outside the stadium when 23,000 fans attempted to enter the ground.

As more and more were ushered in, they fatefully headed down the tunnel that provided access to the two central pens. Police kept the tunnel open. Once people realised the central pens were full it was too late to turn back due to the volume of supporters at the back of the pen.

Gradually, the fans up the front were compressed against the front barrier and it collapsed. Within minutes, Liverpool fans were being crushed to death and the bodies began to pile up.

South Yorkshire Police chief superintendent David Duckenfield immediately claimed that Liverpool fans had broken through an exit gate and forced entry into the stadium. Duckenfield had, in fact, given the order to open the exit gate he was referring to. The statement was retracted that night but the damage had been done. Allegations of drunkenness and violence against the Liverpool fans emerged. The British press ran relentless headlines blaming the supporters for the disaster, and the police refused to take any responsibility.

In the immediate aftermath, Scraton became involved in a relentless pursuit of justice for the victims. The Taylor Report was produced and found that police mismanagement had led to overcrowding, but the subsequent coronial inquest found there was insufficient evidence to prosecute any officer involved. All the while, Scraton was determined to unearth the truth.

A key breakthrough finally came when he tracked down a former police officer who had worked at Hillsborough that day.

"He went out to his car and he came back and he put a box file down and I opened it and there was his statement in three different forms with 53 sentences removed.

"The covering letter relating to his statement … used the words review and alteration. I looked at this and I couldn't believe what I was seeing. The words review and alteration are pretty implicit. There's no doubting what you mean by reviewing something and altering it. When you look at them, a paragraph has a tick by it, that means it's OK. Then you see a paragraph with line after line of pencil through it, or inked out."

Scraton tracked down every statement in the House of Lords reading room, methodically read over each one and decided it was time to write the first edition of his book Hillsborough: The Truth.

Yet it led to nothing.

A review of the new evidence came up empty, and the prosecution of Duckenfield and his deputy at the time, Bernard Murray, failed to punish either man.

That was the year 2000 when the judicial process appeared to have ended, and entered what Scraton calls the "Fallow Years".

"If I was to be quite honest with you on a very personal level, I felt in some way I'd failed the families," Scraton said. "I'd worked with the families for all those years and now felt that, was there something I could've done that I didn't do. I examined myself really. In retrospect there wasn't but it doesn't help you at the time."

The almost decade-long lull was broken at the 20-year anniversary memorial, when roughly 30,000 Liverpool fans turned out at Anfield in 2009 and spontaneously began chanting "Justice for the 96" as they were addressed by culture secretary Andy Burnham.

The Gordon Brown government then committed to reopening the books on the Hillsborough enquiry.

More years of digging followed. Scraton and a team of four researchers reviewed almost 2 million documents after being told rather arrogantly by the police that they would find "no smoking gun".

They did.

"The most important element of it was that we were able to expose at every level the institutionalised abdication of responsibility," Scraton said. "And obviously the failures of the first inquest, the failures of the pathology, the failures in the medical material, the failures in the ambulance service. The failures at every level."

Scraton says he'll never forget the moment he delivered the final report to 400 family members at the Anglican Cathedral in Liverpool.

"I went through methodically the chapters showing how at each level they'd been failed and then came to the final statement that exonerated the fans," Scraton said. "I looked up and as one they stood and they applauded for four or five minutes. People were crying, some had passed out."

Within minutes, Prime Minister Brown made a double apology to the victims – for how they'd met their deaths and for how the system had so comprehensively failed them.

The original inquest verdicts were quashed, an Independent Police Complaints Commission was set up and so was a criminal investigation. And the wheels were in motion for another inquest, which would eventually exonerate all the victims.

In May it was announced Scraton would be awarded the keys of the city of Liverpool, alongside the 96 Hillsborough victims. The Right Rev James Jones, and Kenny and Marina Dalglish were also awarded the honour.

"That was an amazing incredible moving moment to be there with the families, and to hear the reception that they gave," Scraton said. "I would trade everything for that not to have had to happen. What I mean is, I've made some really, really, lifelong, good friends within the Hillsborough families and within survivors, but I would give up all those friendships for Hillsborough not to have happened. That's the emotional side of it. But we are where we are. When the families say you never walked away, I thank them for that. But at the same time, how could you."

 Professor Phil Scraton will deliver a free public lecture on the Hillsborough disaster and its aftermath at UNSW on Monday, October 31 from 6pm in the Ritchie Theatre of the John Niland Scientia Building.