To do so, the jury would have to be sure match commander David Duckenfield was responsible for their manslaughter by gross negligence, the coroner said.
Sir John Goldring has begun summing up nearly two years of evidence into the disaster at the 1989 FA Cup semi-final.
He said the question of how the fans died was "the most controversial".
In considering Mr Duckenfield's conduct, Sir John asked the jury to examine his decision at 2.52pm when he ordered the opening of Gate C, allowing about 2,000 fans to flood into "relatively full" central pens behind the goal on Leppings Lane.
Sir John said the jury had heard evidence that, in broad terms, Mr Duckenfield had said that the gate or gates had been forced and did not say the police had ordered the gates to be opened - what Mr Duckenfield had called a "lie of omission".
He asked the jury to decide whether Mr Duckenfield had lied, and "if you are sure he did lie, you have to ask yourselves 'why?'"
Was it a result of panic or fear of public disorder, he said. Or was it because Mr Duckenfield knew his actions beforehand were responsible for the crushing in the pens, he asked the jury.