Jury nullification is the term for when a jury declines to convict a defendant despite overwhelming evidence of guilt. This can be a form of civil disobedience, a political statement against a specific law, or a show of empathy and support to the defendant.
“It’s not a legal defense sanctioned under the law,” said Cheryl Bader, associate professor of law at Fordham School of Law. “It’s a reaction by the jury to a legal result that they feel would be so unjust or morally wrong that they refuse to impose it, despite what the law says.”
It also doesn’t have to be they all say he did it but don’t punish him, if someone is inclined to get nullification, they can also just push the reasonable doubt angle, poking holes in the prosecution’s case during jury deliberation that the prosecutor will then have no way to know to refute/defend against.