Yeah, I’m gonna guess Polonius is gonna need that mercy.
1) He died without any kind of reckoning that generally these situations require
2) He died spying
3) As a high official close to one (or more) kings, it is not unlikely that he was party to a whole lot of dirty dealings. He could, for example, have just sent Hamlet to his (presumed) death in England. He could have been involved in the regicide of the first king. He’s definitely involved in a whole lot of spying
What else he did, we can’t know – but I’m guessing our man Polonius was never an angel.
The Hamlet Project 