If someone commits a crime, the president has the ability to reprieve their punishment. Reprieving someone means to cancel or postpone they're punishment. The president can grant amnesty, or pardon them from any crimes, to anyone in the country. An example of this is when our president Nixon resigned from presidency after the water gate scandal before he could be impeached. President Ford pardoned Nixon from any crime he could be accused of, so the government wasn't allowed to convict him of anything.