John Dominic Crossan asserts that the crucifixion has a high degree of historical probability.
John Dominic Crossan, Jesus: A Revolutionary Biography (New York: HarperOne, 1994), 163
I distinguish three stages in the development of the passion stories. One is the historical passion—what actually happened to Jesus, what anyone present would have seen. That he was crucified is as sure as anything historical can ever be. . .