Too many Americans don't understand the principles of a free society based on freedoms guaranteed by the U.S. Constitution. In the aftermath of the tragic Baltimore riots in April, the Baltimore prosecutor failed to emphasize the innocent-until-proven-guilty guarantees of the Constitution for those charged with crime.The presumption of innocence is indeed a foundational principle of our justice system. But it is not in the Constitution.
See "Things That Are Not in Constitution":
First, it should be pointed out that if you did it, you're guilty, no matter what. So you're not innocent unless you're truly innocent. However, our system presumes innocence, which means that legally speaking, even the obviously guilty are treated as though they are innocent, until they are proven otherwise.
The concept of the presumption of innocence is one of the most basic in our system of justice. However, in so many words, it is not codified in the text of the Constitution. This basic right comes to us, like many things, from English jurisprudence, and has been a part of that system for so long, that it is considered common law. The concept is embodied in several provisions of the Constitution, however, such as the right to remain silent and the right to a jury.