What principle states that a prisoner may not be treated as convicted unless proven guilty?

The principle that a prisoner may not be treated as convicted unless proven guilty is known as the presumption of innocence. This foundational concept in criminal justice ensures that an individual charged with a crime is considered innocent until evidence presented at trial demonstrates guilt beyond a reasonable doubt. This principle is vital in protecting the rights of the accused and maintaining the integrity of the judicial process. It underscores the responsibility of the prosecution to prove the case against the defendant rather than requiring the defendant to prove their innocence.

This concept reinforces the fairness of legal proceedings and safeguards individuals from wrongful convictions, emphasizing that the burden of proof rests on the state. The presumption of innocence is essential for upholding democracy and ensuring that every individual receives a fair trial.