For the Hillsborough families whose 96 loved ones were killed so horrifically at a football match on a sunny spring day in 1989, a 30-year battle for the truth and accountability has culminated in another outcome they find impossible to accept. They fought for 21 years against the first inquest verdict of accidental death in 1991, finally seeing it quashed in 2012. Then in April 2016, the jury at the new inquests determined that the 96 people were unlawfully killed by the gross negligence manslaughter of the South Yorkshire police officer in command, Ch Supt David Duckenfield, to a criminal standard of proof.

Yet now, following a grim, painful trial and retrial at Preston crown court, in which the families accused the judge of not being impartial, the jury at his prosecution has found him not guilty of, in effect, the same offence: gross negligence manslaughter.

Facebook Twitter Pinterest David Duckenfield arriving at Preston crown court. Photograph: Peter Powell/EPA

For Duckenfield, prosecution inevitably followed the inquests, where he admitted in March 2015 that his multiple “professional failings” at the FA Cup semi-final between Liverpool and Nottingham Forest on 15 April 1989 “led to the deaths of 96 innocent men, women and children”.

The inquest jury based its unlawful killing verdict on the clear direction of the coroner, the senior former Court of Appeal judge Sir John Goldring, that they could reach it only if they were satisfied “that David Duckenfield, the match commander, was responsible for the manslaughter by gross negligence of those 96 people”.

It also demolished the toxic case made by the South Yorkshire police after the disaster: to blame the victims, those 24,000 people who had gone to Sheffield Wednesday’s Hillsborough ground to support Liverpool and been plunged into horror at the squalid Leppings Lane end. That campaign of blame was infamously initiated by Duckenfield himself, who falsely blamed Liverpool supporters even as people were dying from the crush in “pens” 3 and 4 of the Leppings Lane terrace.

Asked what had happened by the Football Association’s chief executive, Graham Kelly, Duckenfield did not tell the truth: that he had ordered exit gates to be opened to allow a large number of people in quickly and alleviate a crush at the turnstiles. Instead, Duckenfield told Kelly that Liverpool supporters had forced a gate open.

At the new inquests, Duckenfield admitted that after exit gate C was opened and more than 2,000 people came in, his own failure to have them directed away from a tunnel, which led to the crowded central pens, caused the lethal crush. He also admitted that he had indeed lied at 3:15pm on the day, then again at a meeting of club directors at about 3:45pm, and that it had been a “terrible lie”.

Quickly relayed to the BBC at the match and broadcast to the nation at 3:40pm, his lie laid the foundation for years of victim-blaming by police that followed: allegations that large numbers of Liverpool supporters arrived late, drunk, loutish and without tickets, and tried to force their way in.

The new inquests jury heard all the evidence over more than two exhaustive years, the longest case ever heard in British legal history. They concluded in their verdicts that the behaviour of those paying spectators looking forward to supporting Kenny Dalglish’s brilliant team did not contribute at all to the disaster.

Yet despite those hard-won legal findings, in Preston the effort began again on behalf of Duckenfield to reverse the inquests’ determinations. Over the many weeks in the gloom of downstairs court number one, Duckenfield’s barrister, Benjamin Myers QC, indignantly denied any failings at all, and even denied that hDuckenfield’s admission of failures on oath four years earlier were really admissions at all, arguing they had been taken “out of context”.

Myers based a defence mostly on arguing it was “bitterly and deeply unfair” to be prosecuting Duckenfield when other factors were to blame – including the safety flaws of the Leppings Lane terrace and its vile “pens”, the “defective” police plan Duckenfield inherited and radios not working properly – and resurrecting the old allegations against the victims. Myers also criticised other police officers who had worked to Duckenfield’s command, including one, Insp Harry White, whom Duckenfield had explicitly said in his evidence at the inquests he did not blame or criticise.

Hillsborough victims: the 96 people whose lives were cut short Read more

The hole in the heart of these proceedings, the question about the British legal system looming over every miserable day for the families, was why it allows and requires this: established truths, determined by a jury on comprehensive evidence given on oath in front of a senior judge, erased and up for grabs again.

The Preston trials were marshalled by Sir Peter Openshaw, a veteran judge of the criminal court circuit in Lancashire. Although the new jury was effectively deciding the same questions about the same disaster, Openshaw gave them the required legal direction that previous findings – about which they were not informed anyway – were “quite irrelevant” because “the rules and procedures were very different to a criminal trial”.

So a blank page was presented to a new jury, as if no truths had been accepted over 30 years, through the families’ fight, fury and an infinity of tears. Repeatedly, Myers was on his feet alleging that Liverpool supporters had indeed arrived late; that many were without tickets and many had had a drink; that they pushed, misbehaved, refused to accede to police instructions and tried to cheat their way into the ground.

Facebook Twitter Pinterest Fans try to get to safety at Hillsborough during the 1989 semi-final. Photograph: Hillsborough Inquests/PA

In the adversarial system, a defendant can present any case to a court within the rules as applied by the judge, and it is up to the opponent, here the Crown Prosecution Service, to challenge them. The only evidence that counts is what the two opponents have presented in that courtroom, often in hasty responses.

The most glaring example of the departure from established truths this can create came in the first trial, which culminated in a hung jury. The CPS lead barrister, Richard Matthews QC, had decided not to make much of Duckenfield’s lie on the day, except, almost in passing, the bare fact that he said it. This was a legal assessment that bewildered and exasperated the families. In Openshaw’s summing up, the judge suggested to the jury that Duckenfield had not, in fact, lied after all. He said that Duckenfield appeared to have genuinely formed the impression that supporters had forced a gate, and that given the circumstances, it was “not at all surprising”. The jury was never told that Duckenfield had actually admitted in previous proceedings four years earlier that he had told a terrible lie.

On the question of Duckenfield’s experience, there was consideration of large events whose police operations he had commanded, including a Billy Graham rally and a Bruce Springsteen concert at Sheffield United’s Bramall Lane ground. Duckenfield had acknowledged those at the inquests, but explained: “They were different to the football matches of the time.”

Referring to that, Openshaw told the jury: “As [Duckenfield] said, the atmosphere of those events – and the kind of people attending them – were very different from those attending a semi-final.”

Margaret Aspinall, the chair of the Hillsborough Family Support Group, whose 18-year-old son, James, was one of the 96 people killed, said family members hearing that were devastated, and considered the summing up “one-sided”.

She said: “I found it disgusting. Like the judge was saying my lovely innocent son and all our 96 were a different kind of people, hooligans, and their families. Even in death, after 30 years.”

Facebook Twitter Pinterest Casualties being carried away after the crush at Hillsborough. Photograph: Operation Resolve/PA

In heated meetings over the summer, many family members called on the CPS to improve their performance, and to apply for the judge to be replaced. The CPS did strengthen their case somewhat, including by emphatically presenting Duckenfield’s lie in evidence this time. But Matthews still left out large areas that had been considered by the inquests jury, crucially including whether other police officers’ 1989 evidence was reliable. He declined to challenge Openshaw continuing as the trial judge.

When the retrial began on 7 October, Openshaw was in his position again, on the raised, wood-panelled stage. Duckenfield was in the courtroom, not in the dock allocated for criminal defendants; the judge allowed this throughout, explaining in a ruling that it was part of making allowances for Duckenfield’s post traumatic stress disorder and anxiety.

On October 24, the judge told the jury in some detail that Duckenfield had reported poorly with a chest infection, including that he had driven himself to hospital although he had been told to call an ambulance as a precaution. “It’s not his fault, poor chap,” Openshaw said.

That was followed by a direction to the jury that if they thought Duckenfield was not showing any emotion as they heard about the horrific crush, and as bereaved parents gave evidence about the loss of their children, it could be explained due to him suffering from PTSD.

The families, who have suffered endless grief and trauma for 30 years, reacted with dismay to these interventions, and asked if an accused in a criminal trial would normally be referred to as “poor chap”.

In his summing up of the evidence, Openshaw made a similar reference to the Bruce Springsteen concert and Billy Graham rally, telling the jury that Duckenfield had said of them at the inquests: “The nature and tone of the events – and indeed the people who attended – was completely different from a semi-final.”

Facebook Twitter Pinterest Fans were allowed on to the pitch as the Hillsborough tragedy unfolded. Photograph: PA

He did take the jury through Duckenfield’s admissions at the inquests, but added that Duckenfield had “prefaced” many of them by saying he was conceding to failures only with the benefit of hindsight. He did not explain to the jury that the inquests barristers had sought to break that down, asking Duckenfield if he accepted that he failed according to how competent he should have been at the time.

Openshaw cited Myers’ argument that the admissions had been “wrung out” of Duckenfield over six days of questioning. But the judge did not explain that many of Duckenfield’s acknowledgements of failure were in fact made on the first two days, to Christina Lambert QC, counsel to the inquests. Nor that Duckenfield’s acceptance that his own “professional failings led to the deaths of 96 innocent men, women and children” was made to his own barrister, John Beggs QC.

Throughout, the jury was told to remove emotion from their consideration, and very little was heard of the 96 people themselves, whose terrible deaths Duckenfield was accused of causing. Aged from 10 to 67; sons, daughters, sisters, brothers, 25 fathers, one mother; at the inquests their lives and personalities had been remembered by their families with loving, vivid personal statements. In Preston the jury was told almost nothing about them, beyond their names being read out at the beginning.

The families suffered their catastrophic loss while also having to fight their way through the justice system against the lies, for the truth about how the 96 were killed that terrible day. At the second inquests, they were granted exceptional funding by Theresa May’s Home Office, so for the only time had an army of their own lawyers who battled their way to vindication.

Here they were in the hands of the legal establishment, watching a stripped-down framing of another new set of truths, as if nothing had ever been decided or admitted before, in 30 years.