An inquest has found that the 96 Liverpool fans who died during the 1989 Hillsborough disaster were killed unlawfully, bringing an end to the 27-year wait for justice for their families.

Nine jurors found that match commander David Duckenfield was “responsible for manslaughter by gross negligence” and that mistakes made by the police force during the 15 April 1989 FA Cup semi-final added to the severity of the situation.

After almost three decades of campaigning from the families of those who perished, the jury exonerated the behaviour of the Liverpool fans and agreed that those going to watch the match at Sheffield Wednesday’s home ground did not contribute to the danger.

Unanimous verdicts were given on all but one of the 14 questions posed by the inquest. Coroner Sir John Goldring said he would accept a majority decision about whether the fans were unlawfully killed. Seven of the nine jurors agreed they were.

In addition, the jury concluded that defects at the stadium contributed to the disaster and that there was an error in safety certification for Hillsborough.

Labour MP Andy Burnham – who is from Liverpool and has campaigned with the Justice for the 96 group – said the tragedy was the “greatest miscarriage of justice of our times” but added that after 27 years justice was finally served.

“Next must come accountability,” added the former health secretary. “For 27 years this police force has consistently put protecting itself above protecting those hurt by the horror of Hillsborough. People must now be held to account for their actions and prosecutions must now follow.”

Chief constable of the South Yorkshire police David Crompton said the force would “unequivocally accept the verdict” and the wider findings and admitted that the policing during the match was “catastrophically wrong”.

“Today, as I have said before, I want to apologise unreservedly to the families and all those affected,” he added.

Prime minister David Cameron tweeted: “I would like to pay tribute to the extraordinary courage of Hillsborough campaigners in their long search for the truth.”