The jury in the trial of Hillsborough match commander David Duckenfield has been unable to reach a verdict.
Former Ch Supt Duckenfield, now 74, had denied the gross negligence manslaughter of 95 Liverpool fans in the 1989 disaster.
Ex-Sheffield Wednesday club secretary Graham Mackrell has been found guilty of a charge under the Health and Safety at Work Act.
Jurors at Preston Crown Court spent eight days deliberating.
The Crown Prosecution Service (CPS) has indicated it will seek a retrial for Mr Duckenfield, of Ferndown, Dorset.
During the 10-week trial, jurors heard that 96 men, women and children died as a result of a fatal crush on the Leppings Lane terrace on 15 April 1989.
Under the law at the time, there can be no prosecution for a 96th victim, Tony Bland, as he died more than a year and a day after the disaster.
The jury deliberated for more than 29 hours but was unable to agree whether Mr Duckenfield was guilty or not guilty of manslaughter by gross negligence.
The former South Yorkshire Police officer has always denied the charges.
Sue Hemming, legal director of the CPS, said the trial had been “incredibly complex” and she recognised “that these developments will be difficult for the families affected by the Hillsborough disaster”.
After discussions the CPS has decided to seek a retrial against Mr Duckenfield, she added.
The trial heard Mr Duckenfield ordered the opening of exit gates at the Leppings Lane end of the ground at 14:52 BST, 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.
Prosecutors alleged Mr Duckenfield had “ultimate responsibility” at the ground and should have made “key lifesaving decisions” on the day.
But his defence argued the case against him was “breathtakingly unfair” and said Mr Duckenfield had “tried to do the right thing”.
Mr Mackrell, 69, was convicted of failing to discharge his duty under the Health and Safety at Work Act, by a majority of 10 to two.
He was accused of failing to take reasonable care to ensure there were enough turnstiles to prevent large crowds building up.
The court heard there were seven turnstiles for the 10,100 Liverpool fans with standing tickets for the match against Nottingham Forest.