I had jury duty last week.
(I think I need something right in here.)
In a trial by jury, the jury is a representation of the general public. The prosecution must prove to the representatives of the population served by the court beyond a reasonable doubt that the defendant is guilty. That is the burden of truth. It's the closest we can get to democracy without polling an entire city, county or state for every court case.
In theory, the sovereignty of the government, and, by extension, the court, lies in the power of the people. By placing the burden of the discernment of truth on the sovereignty of the people, our judicial system attempts to imitate Divine justice, but our understanding of justice is flawed. This is a fatal flaw for those whom the law fails to judge justly.
I've heard it said that the law does not exist for the just, but for the unjust; the just carry the law in their hearts and do not need to call it from afar. "And we also know that the law is not for the righteous but for lawbreakers and rebels, the ungodly and sinful" (1st Timothy 1:9). But in this impure world, no one is purely just; no one is righteous apart from the Law. The Law, therefore, is for us all.