To be more specific:

US law states that the defendant is considered innocent until PROVEN guilty. The jury's job is to consider the evidence and the facts, and determine if the defendant has been appropriately proven guilty by the prosecutor.

The defendant cannot be charged if the defendant did not appear to break any laws. The laws in this case do not change.

The jury determines if prosecutor has provided sufficient proof that the defendant broke a law.

The jury argees or disagrees with the prosecutor's arguments, based on which the defendant is acquitted or found guilty.

When this happens, the jury is NOT saying that the defendant did not break the law. The law is a matter for the State and the Judge to apply. The jury does not apply the law. The jury ONLY determines if the facts are sufficient for a guilty verdict. There are many cases where the law was indeed broken by the defendant, but there was not sufficient evidence to prove guilt. There are also cases where the defendant did not break the law but the jury determined that he/she was guilty of the charge, given the evidence presented as proof at the trial.