Federal pardons in the United States

In the United States, federal pardons are granted only by the president, pursuant to authority under the U.S. Constitution to grant "reprieves and pardons for offenses against the United States". Pardons extend to all federal criminal offenses, except in cases of impeachment, and entail various forms of clemency, including commuting or postponing a sentence, remitting a fine or restitution, delaying the imposition of a punishment, and providing amnesty to an entire group or class of individuals.

Source: Wikipedia — Federal pardons in the United States (CC BY-SA 4.0)