Yep. It's called "jury nullification". They decide to acquit despite the evidence. I once saw this in a NYC trial wherein a shopkeeper shot an armed robber to death, and the D.A. charged him with unlawful possession of a handgun. The jury simply acquitted him. The judge and D.A. were pissed. Nothing they could do.
Except declare a mistrial if a juror admits they acquitted because they don't approve of the law. Jury nullification is not legal in the US. I think that's an outrage, but judges will throw you off a jury or set aside a jury verdict if they think that's what's going on.
Jury nullification was one of those rights of Englishmen our ancestors thought they were fighting to preserve.