Settled 150 or so years ago. ‘Ex parte Garland’:
https://www.law.cornell.edu/supremecourt/text/71/333
...9. The power of pardon conferred by the Constitution upon the President is unlimited except in cases of impeachment. It extends to every offence 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. The power is not subject to legislative control.
10. A pardon reaches the punishment prescribed for an offence and the guilt of the offender. If granted before conviction, it prevents any of the penalties and disabilities consequent upon conviction from attaching; if granted after conviction, it removes the penalties and disabilities and restores him to all his civil rights. It gives him a new credit and capacity...
Got it. Thanks for straightening me out. University of FR.
Then Arpio should just walk.