Technically the Jury already has the right to do this*, it's called
Jury Nullification. Letting the prosecutor, judge, or anybody else know you're aware it's possible is the fastest way to get eliminated from jury duty, the legal system hates it when jurors throw their weight around.
No, jury nullification is something else entirely, and it isn't explicitly part of the law either. Jury nullification is the Jury ignoring the law and finding the accused innocent.
What I am talking about is the jury finding that not only is the accused innocent, but also that the accusation is so absurd that the only reason to bring the case to court is malice.
One is "He is innocent because the law is stupid" the other is "He is so innocent that the prosecutor needs a spanking for bothering him with this."
However I would like Jury nullification to be explicitely part of the law, so you could actually tell/ask the jury for it without the judge punishing you. That and have repeated jury nullifications repeal a law, or at least send it back to the senate for review.