The document which guarantees citizens of the United States fair trials is d) the Bill of Rights. This can be seen in the Articles numbered eight and nine, where it is entailed that "every citizen has a right to a speedy and public trial, to be informed of the nature and cause of the accusation and to be confronted with the witnesses against him, to have a compulsory process obtaining of witnesses in his favor, and to have the assistance of counsel for his defense."
