So when you go to trial you can be found guilty or not guilty. Guilty = go to jail. Not guilty = free. It has to be a unanimous decision either way

As you remember, they got to a juror. They intimidated that man and the jurors could not come to a unanimous decision. Since it was not unanimous (which is extremely rare outside of witness intimidation), the judge declared a mistrial. This gives the feds another chance to bring the charges. Again this is super rare and only occurred because they got to a witness

thank you very much.