Almost 30 years after 96 people were killed at the FA Cup semi-final between Liverpool and Nottingham Forest at Sheffield Wednesday’s Hillsborough football ground, the police officer who was in command of the match, David Duckenfield, will on Monday stand trial on a criminal charge of gross negligence manslaughter.

Duckenfield was newly promoted by South Yorkshire police to the rank of chief superintendent when he took charge of safety at the semi-final, which was played on 15 April 1989. He is charged with failing in his duty to take reasonable care for the safety of spectators at the Leppings Lane and north stand areas of Hillsborough designated for Liverpool supporters, to protect them from overcrowding and crushing.

The showpiece football occasion was attended by 54,000 people, 24,000 of them Liverpool supporters allocated those sides of the ground. The indictment alleges that Duckenfield’s breach of his duty of care, to prevent people being crushed in “pens” 3 and 4 of the Leppings Lane terrace, amounted to gross negligence, and was “a substantial cause” of the deaths.

Graham Mackrell, the Sheffield Wednesday club secretary and safety officer at the time the disaster happened, will stand trial alongside Duckenfield, on two counts of breaching his duties under safety legislation.

Mackrell is charged with failing to agree with the police the number of turnstiles to be used for Liverpool supporters’ admission to the Leppings Lane terrace, an alleged breach of the club’s safety certificate under the Safety of Sports Grounds Act 1975, the first ever prosecution under that legislation. He is also charged with failing to take reasonable care of people’s safety under the Health and Safety at Work Act 1974, including by failing to draw up contingency plans for coping with a large build-up of spectators outside the ground.

The trial at Preston crown court, which will be presided over by the judge Sir Peter Openshaw, is scheduled to last four months, due to conclude in May. The 30th anniversary of the disaster is on 15 April , while the trial is almost certain still to be proceeding. Openshaw is expected to pause the trial during the week of the anniversary, for commemorations and remembrances of the disaster and the 96 people who were killed.

The Crown Prosecution Service charged Duckenfield and Mackrell in June 2017, based on a police investigation into the disaster, Operation Resolve, which was set up after the report by the Hillsborough Independent Panel in September 2012. The last Labour government set up the panel in 2009, after the 20th anniversary of the disaster, and its work continued from 2010 under the new Conservative-Liberal Democrat coalition government. The criminal charges followed inquests into the 96 deaths, held in Warrington from 31 March 2014 to 26 April 2016, the longest case ever heard by a jury in British legal history.

Both Duckenfield and Mackrell have already pleaded not guilty to the charges in pre-trial hearings. The maximum sentence for manslaughter by gross negligence, if Duckenfield is convicted, is life in prison. The maximum sentence for the first charge faced by Mackrell is two years in prison; for the second he faces, the maximum is an unlimited fine.

Duckenfield is charged with a single count of unlawful killing, manslaughter by gross negligence, in relation to 95 of the people who died. No charge could be brought in relation to the death of the 96th victim, Tony Bland. He was 18 when he went to Hillsborough to support Liverpool at the semi-final, and suffered severe, critical brain damage due to loss of oxygen in the crush on the Leppings Lane terrace. He was taken to hospital, where he remained on life support for four years. The life support was turned off in 1993 following a court application by Airedale NHS Trust, supported by his parents, that it would not be unlawful to do so, based on medical evidence that the brain damage was irreversible and he could never recover his faculties.

Duckenfield has not been charged in relation to Bland’s death because, according to the law in 1989, a criminal charge of manslaughter could not be applied if the victim died more than a year and a day after the alleged breaches of care occurred.

The first day, at least, of the scheduled trial is expected to be concerned with selecting a jury of 12 people. The lead barrister for the Crown Prosecution Service, Richard Matthews QC, is expected to open the case against Duckenfield and Mackrell on Tuesday or Wednesday this week.

Three other men face criminal charges in relation to the disaster in a separate trial scheduled to start in September. Donald Denton, a former South Yorkshire police chief superintendent at the time, Denton’s then deputy, former chief inspector Alan Foster, and the then South Yorkshire police solicitor, Peter Metcalf, are charged with doing acts following the disaster with intent to pervert the course of justice. They deny the charges.