What is the difference between and pardon and amnesty? When someone has been prosecuted and convicted of a crime, if they want to remove the conviction, they must seek a pardon. In state court their are exceptions to this rule, like exungements for summary offenses, but in federal court, you must get a pardon to remove a conviction.
Amnesty is where a person or group of people are told that they will not be prosecuted for a particular offense if they comply with terms of the amnesty, or simply admit to their role in the alleged crime. For example, the government can say that on a certain day all citizens who possess illegal firearms can turn firearms in to a police station and they will not be prosecuted. The idea that people are possessing the illegal weapon, but the government agrees not to prosecute, is a form of amnesty.
Always remember, the state and federal governments are separate sovereigns, so you can be prosecuted in one court even if you are granted amnesty in another.