Pontius Pilate did NOT kill Jesus. Jesus was killed by Caifass the archpriest and other members of priest councils, but the main "murderer" was Judas Iskariot.
The Jesus himself mentions that Pilate is innocent ("you wouldn't have any power over me if it weren't given to you from below, so greater sin has the one who betrayed me"). He also says "alas the one through which the Son of Man will be condemned, it would be better for this man never to be born".
As Pilate said, "I wash my hands, I am not guilty the blood of this just one."
Haraldur: That's quote from Passion. It sounds stupid in english, but in some languages having latin-esque grammatics, it makes sense, as "which" is refered to "which one", "what", that's at least how it looks in polish, and we have hell of a grammatics.
The meaning is "What is truth?"
Or maybe it should be "Quid est veritas" in direct translation, but I am assured the quote I brought is right.