The Jewish Sanhedrin held the trial of Jesus (a fellow Jew), not the Romans. Caiaphas, not Pilate, presided over that trial.
Pontius Pilate interrogated Jesus directly and found no wrongdoing on Jesus's part. Nevertheless, the Sanhedrin demanded Jesus's execution. Pilate washed his hands of the whole affair, but to keep from having an open revolt because of the Sanhedrin's position, he allowed Jesus to be crucified. He was not Jesus's executioner, nor was he even present at the crucifixion.
Why do people always try to blame the Romans? The answer to that is obvious, and you know it.