Bereaved families have branded the trial of Hillsborough match commander David Duckenfield a "disgrace" after he was cleared of the gross negligence manslaughter of 95 Liverpool fans who died at the 1989 FA Cup semi-final.
There were gasps as the seven women and three men on the jury at Preston Crown Court returned its verdict on Thursday, following a trial which lasted more than six weeks.
Margaret Aspinall, whose 18-year-old son James died in the disaster, has written to the judge Sir Peter Openshaw to say she was "deeply concerned about what I perceive to be a lack of impartiality in your dealings with the defendant in front of the jury".
Mrs Aspinall, chairwoman of the Hillsborough Family Support Group, wrote the letter following a direction from the judge that the jury should draw no adverse inference from Duckenfield's "resilient, passive and expressionless" presentation in court as he suffered from post-traumatic stress disorder.
She said after the verdict: "The families know who is guilty.
"Our city knows who is guilty. He can walk around now and get on with his life with a not guilty verdict.
"To me that is a disgrace," she told reporters at the Cunard Building in Liverpool.
Christine Burke, the daughter of Henry Burke who was killed in the tragedy, stood in the public gallery after the verdict was announced and tearfully said to Sir Peter: "With all due respect, my lord, 96 people were found unlawfully killed to a criminal standard.
"I would like to know who is responsible for my father's death because someone is."
While Mary Corrigan, mother of 17-year-old victim Keith McGrath, shouted: "Stitched up again", while other family members were in tears.
Inquests in 2016 found the 96 men, women and children who were fatally injured on April 15 1989 were unlawfully killed on the basis that Duckenfield, 75, breached his duty of care and was found grossly negligent.
Under the law at the time, Mr Duckenfield was not charged over the death of the 96th victim Tony Bland, because he died more than a year and a day after the disaster.
Ian Lewis, partner at JMW Solicitors LLP who represented Duckenfield, said: "David is of course relieved that the jury has found him not guilty, however his thoughts and sympathies remain with the families of those who lost their loved ones."
Steve Kelly, whose brother Michael, 38, died in the tragedy, told the press conference: "A higher judge will have the last say on this. God bless the 96."
The retired chief superintendent stood trial earlier this year, but the jury was discharged after failing to reach a verdict and a retrial was ordered.
The court heard he ordered the opening of exit gates at the Leppings Lane end of the ground at 2.52pm, eight minutes before kick-off, after the area outside the turnstiles became dangerously overcrowded.
More than 2,000 fans entered through exit gate C once it was opened and many headed for the tunnel ahead of them, which led to the central pens where the crush happened.
Operation Resolve was established to investigate the incident and concludes at the end of the year.
Duckenfield did not give evidence in the trial because, the court heard, he was suffering from post-traumatic stress disorder.