"Their shouts prevailed. So Pilate decided to grant their demand." — Luke 23:23-24
For the Roman governor Pilate, it was not that he might have known better if he'd just had more information. It was not that he might have acted differently if he'd had a better understanding of how things worked among the people he ruled in the province of Judea. The case that confronted Pilate was not vague or unclear.
Several times Pilate gave the Jewish high priests the chance to submit all the evidence they could. Repeatedly Pilate recognized that the evidence added up to no case at all under Roman law. Pilate had personally interrogated Jesus. Perhaps he figured that something Jesus might say would prove incriminating, even if the priests' evidence had not. After these thorough reviews, Pilate returned each time with the same judgment. There has been no crime; there is no basis for charges, no reason for a sentence of any kind. The obvious legal outcome of this case was to release the defendant.
But Pilate sentenced Jesus to death by crucifixion. Why? Because he recognized the power of the priests. They could make or break his governorship; they could cooperate in keeping things running smoothly in Judea, or they could make things difficult. Jesus had no power that mattered to Pilate. Jesus could be discarded, dispensed with. And so he was. This was, in God's design, for our sake.