What legal principle prevents a person from being tried again for the same crime after being found not guilty?

The principle that prevents a person from being tried again for the same crime after being found not guilty is known as Double Jeopardy. This legal doctrine is enshrined in the Fifth Amendment of the U.S. Constitution, which protects individuals from being subjected to the anxiety, expense, and ordeal of a second trial for the same offense once a verdict of not guilty has been reached.

Double Jeopardy ensures that once a person is acquitted, they cannot be prosecuted again for that particular crime, fostering a sense of finality in the legal process. This principle is fundamental to the concept of fair trials and upholds the integrity of the judicial system, ensuring that the government cannot repeatedly attempt to convict an individual for the same act after a jury has delivered a verdict of innocence.

The other concepts listed, while important in legal contexts, do not apply directly to the issue of being tried for the same crime. Due Process relates to the fair treatment through the judicial system, Equal Protection ensures that individuals are treated equally under the law, and Res Judicata concerns the binding effect of a final judgement in civil cases, not criminal prosecutions.