The Writ of Habeas Corpus and the many other provisions regarding criminal trials found in the Bill of Rights help to ensure that the state does not punish people without good cause.
But other guarantees that operate before and during a trial would be worthless if a suspect could be detained indefinitely while waiting for a dithering or malicious prosecutor to begin proceedings. Pursuant to the 6th Amendment’s guarantee of a speedy trial, if the state delays too long, a judge may dismiss an indictment against a prisoner in order to end his detention. In such cases, a prosecutor, if he wishes to proceed with his case, will have to submit a new indictment. Moreover, if the court believes that the defense has been harmed by the delay, then it may dismiss the indictment without the possibility of a second one.
Similar to the 6th Amendment’s guarantee of a speedy trial, its promise of a public trial was intended to forestall possible abuses by the state. In theory, a secret trial could be just as fair as a public trial. But as noted by Justice Harlan, writing in Estes v. Texas (1965): “the public-trial guarantee embodies a view of human nature, true as a general rule, that judges, lawyers, witnesses, and jurors will perform their respective functions more responsibly in an open court than in secret proceedings.”
The benefits to be gained by a speedy and public trial were uncontroversial to early Americans. During the ratification process of the Constitution, Virginia had requested that an amendment be added that would ensure a “fair and speedy trial,” and New York had recommended guarantees for “speedy, public” criminal trials. Madison’s original proposal for a Bill of Rights included “the right to a speedy and public trial.” The First Congress did not need to debate the desirability of this provision, and it was ultimately adopted into the 6th Amendment in the exact language that Madison had proposed.