Would you care to explain exactly how He can know this
the most simple answer is that he destined it. When? not at the beginning but when man's evil was sufficient such that such a prediction was possible, if there was a prediction at all.
As I've said, I have no problem with God destining the specific way in which evil works out provided that the necessity of the evil is not traced back to him.
However, I don't know that we should believe that this was destined. I'm fine with it if there is a scripture that you could point to, and I'm sure that there is, but I doubt it is a prophecy such that it had to come to pass. If it was though, then of course that is the earliest that it was destined.
So how can God know that there would be evil men to do such. one reasonable answer is out of statistical necessity, which is a necessity that allows for indeterminism and does not require reprobation or that any particular should sin without lending himself to a certain degree of depravity such that he should willingly take an innocent man to be condemned to death.
That necessity arose from the rebellion of God's people though and was not foreknown before the people went down a certain road.
And there is always the possibility that this was a conditional prophecy, (again if there was such a predictive prophecy at all).
concerning an earlier post of yours.
Though I’d note that the WC also, in addition to that bit you just quoted, states that God does this in such a way that no violence is done to the will of the creature, etc.
the problem that I was citing is not directly with the WC's view of free will. It's with the role of foreknowledge that you posited earlier.
If we consider God and what He knows prior to Creation, and grant that He has foreknowledge of everything that will come to pass, whether those things will be caused by Him directly or freely performed by creatures, then if He proceeds and effectuates that potential creation, by virtue of His certain foreknowledge, everything that comes to pass has been predestined.
The WC explicitely says that God does not predestine according to foreknowledge. For many Calvinist theologians, including Calvin I believe, God's foreknowledge is based solely on predestination and there is no fact of the matter about the way creation will be apart from that. God doesn't look at the free actions that will be taken if He does such and such. He ordains everything precisely according to his will. What you've described sounds more like molinism.