David Duckenfield, the Hillsborough match commander, has appeared in court at the start of his trial for the gross negligence manslaughter of 95 Liverpool fans.
The 74-year-old former police chief superintendent sat alongside former Sheffield Wednesday club secretary Graham Mackrell, who is charged with contravening the stadium's safety certificate and a health and safety offence, as proceedings began in Preston Crown Court.
When the hearing began 100 potential jurors were brought in, sitting in the jury box, public gallery and dock.
Judge Peter Openshaw told the jury panel: "Public opinion in this country strongly supports a system of trial by jury, particularly in serious cases.
"I know that your jury summons suggests jury service is usually only for two weeks but some trials take longer than two weeks and I must find a jury, if I can, to try an important case which might last three or even four months."
Potential jurors were given a questionnaire to assess whether they would be suitable to serve.
The questionnaire said: "In this case one defendant is charged with manslaughter and another with two health and safety offences arising out of the Hillsborough stadium disaster at the FA Cup semi-final between Liverpool and Nottingham Forest played in Sheffield as long ago as April 15, 1989."
The form was made up of 18 questions including whether they were supporters of Liverpool, Everton, Sheffield Wednesday or Nottingham Forest football clubs and whether they or close family members or friends had ever been police officers or been employed by the police, Crown Prosecution Service, Independent Police Complaints Commission or any criminal justice agency.
The two defendants, who both wore suits and sat alongside solicitors, were asked to stand so the panel could see whether they recognised them and a list of witnesses to be called was read out.
Potential jurors were also asked whether they had health problems or had any pre-booked holidays while the trial was due to sit.
Judge Openshaw warned them not to look up anything about the disaster on the internet. The court was adjourned while potential jurors filled in the questionnaires.
Fourteen family members sat in court. Other relatives watched from a court annexe while some were able to watch via videolink at the Cunard building in Liverpool.
Ninety-six men, women and children died in the crush in pens at the Leppings Lane end of the Sheffield Wednesday ground. There can be no prosecution for the death of the 96th victim, Tony Bland, as he died more than a year and a day after he was injured.