Originally Posted by Axeman

He can pardon before, during or after. It would be a terrible look though. Only thing he can't do is pardon himself if impeached.

" Accordingly, the Constitution simply provides that the President ''shall have power to grant reprieves and pardons for offenses against the United States, except in cases of impeachment'' (Article II, section 2).

The leading Supreme Court case is Ex parte Garland (1867). Justice Stephen J. Field, writing for the Court in a 5-4 decision, held that the President's pardoning power is ''unlimited,'' and ''It extends to every offense known to the law, and may be exercised at any time after its commission, either before legal proceedings are taken, or during their pendency, or after conviction and judgment.'' "

Constitution Allows Pardons Before Conviction - NYTimes.com

Originally Posted by Bladewire

It's called a premptive pardon. Nixon was pardoned before being charged with a crime

"In the case of President Richard Nixon, he was granted a pardon for any crimes he might have committed during the Watergate scandal, even though Nixon wasn?t charged with or convicted of federal crimes. (This is known as a pre-emptive pardon.) Another way a person can receive clemency after a conviction is through a commutation of a sentence."

https://en.m.wikipedia.org/wiki/Pardon