My mom grew up in a predominately Jewish neighborhood and became a Catholic at a very young age. I am something of what we call a "Cashew". I admire the Israelis a great deal. As to who killed the Christ, the Romans put Him to death but it had to be done.
I often get into arguments with fellow believers over this sort of thing. Judas had no real choice in the matter, did he? Nope. How could a loving God condemn Judas to Hell for eternity for being a cog in the wheel of God's plan for redemption? Doubtless Judas had tremendous remorse and was so grief stricken that he hung himself. But if you think about it, given the circumstances and the man he betrayed, who wouldn't feel so crappy as to seriously consider hanging themselves? That's a big burden to be placed on anyone's shoulders. Not quite as big as the cross but certainly too much for a mere man to carry the rest of his life.
I tend not to worry too much about such things nor do I hold accountable people who were not responsible for and to be honest not even alive/around when these things occurred. That is something morons are famous for. Hated filled, greedy men will hold any and everyone responsible for crimes and atrocities that were committed years or even generations ago but only when there is something to be gained by doing so, e.g. political power, a land grab, redistribution of wealth, etc.
Like Mohammed or any number of Popes and others of their ilk, they will do this only today it's not performed in the name of "God" (because they despise any "God" save themselves) but rather they use terms like "fairness" or "restitution".