Lay people and the media (who should know better) often claim that they (or someone else) were found innocent even though technically this has never happened in a criminal trial in the history of the United States. That’s because in our justice system, there are only two possible verdicts in criminal case: guilty and not guilty. If you are found guilty it merely means that there was enough evidence presented in your trial to convince the trier of fact (be it a judge or a jury) that there was proof “beyond a reasonable doubt”. This is an abstract concept, and hence, is subjective. If you would pause or hesitate in making an important decision in your life, that would be “reasonable doubt”; otherwise it would be “beyond a reasonable doubt” and a guilty verdict is rendered. Hence, by default, a not guilty verdict occurs when the tier of fact thinks that there is reasonable doubt.
However, it does NOT mean that they were proven “innocent” since our system does not have that possible verdict (or standard). It merely means “that there was not evidence to prove them guilty.” This sounds subtle but there is more of a difference than it appears. When someone is found “not guilty” it is still possible that they committed the crime while being found “innocent” suggests that it is not possible that they committed the crime. As you can imagine, this would be very difficult to prove which is the main reason why the founders of our country left it out as a possible verdict. In addition, it would have no additional legal effect than “not guilty” since all that matters is that they were not found “guilty.” Also, as you have heard several times before — the defendant never has to prove his innocence.