Final answer:
The person against whom criminal charges by the government are filed is known as the defendant, who enjoys Sixth Amendment rights such as a fair trial and counsel assistance.
Step-by-step explanation:
In the context of the United States legal system, the person against whom criminal charges are filed by the prosecuting state or federal government is known as the defendant. This individual is charged with violating the law and must face the legal consequences if found guilty. Under the adversarial system, the government is the plaintiff in criminal cases, and it has the burden of proof. The defendant is entitled to a range of protections under the Sixth Amendment, such as the right to a speedy and public trial, the right to be informed of the charges, to confront witnesses, to obtain witnesses in their defense, and to have the assistance of counsel.
Moreover, the Fifth Amendment stipulates that for serious crimes, a grand jury must indict the accused for them to be tried in federal court, unless the state has an alternative fair process. The distinction between criminal and civil law, as well as the rights of the accused are foundational to the American judicial system, ensuring that all criminal prosecutions maintain the principles of fairness and justice.