Selene...
Try to understand...
If the killer choose to kill than he is responsible for it because he IS a killer, for that sin came out of his heart. And even if he didn't commit that sin he would still be a sinner because he is a killer (assuming we are talking about one).
Just like a lion is a killer because killing lives withing it's nature.
Is the lion to blame because of its killing nature? Of course not because he is how the creater made him, but in spite of it he is still a killer... the fact that he did not choose to be a killer does not makes him a non-killer because that's precisely what GOD made in him; a natural killer.
Just like this, a saint is a saint because HE made him a saint, and a sinner is a sinner because HE made him sinner...all within HIS plan to serve His own purpose.
And once that plan it's over the sinner will go to it's place, and the saint will go to it's place.
But, being GOD full a justice HE tells all man to repent (even tough HE knows they will not) so that everyone who claims free will be confronted in the last day with what their free will made for them.
So even the wicked will be judge by it's own terms (free will) and get convinced of their own sins ... and HIS justice will shine...
HE didn't have to do any of this because all are HE's, but HE gives them all this chance "if you can, then do it" so it be notorious that they really are what they were made, that they belong to the creator and are HIS work.
The elect know there's no free will, and will live by the grace of GOD in who they trust with all his heart, but the wicked who claims free will because he does not believe that he is enslaved will be judge by it's choices and if he did or did not believe in the gospel (which is what I'm talking right now).
But the truth is, this is not about blames, it's about what you are, not what you do... it's about being a son of GOD or not.