Can you direct us to a link for the exact law about that?
"A pardon can also be granted to a class of people, such as those involved in the Whiskey Rebellion. In US v Klein (80 US 128), the Supreme Court upheld such blanket or group pardons — President James Carter pardoned all Vietnam draft dodgers."
So what 'class of people' could Barry Hussein pardon? Illegals want Barry to pardon them, but the problem is they are citizens of another country! However, there are many dangerous, criminal, and guilty as seen groups that Obama could pardon. Use your imagination. That's when it get scary.
“Can you direct us to a link for the exact law about that?”
A president can pardon anyone for any federal crime whether or not they have been accused.
In 1866, the Supreme Court ruled in Ex parte Garland that the pardon power “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.” (In that case, a former Confederate senator successfully petitioned the court to uphold a pardon that prevented him from being disbarred.) Generally speaking, once an act has been committed, the president can issue a pardon at any time—regardless of whether charges have even been filed.