Jesus had done nothing wrong.  Pilate did not first ask Him about His supposed crime, but His identity.  In asking if He was the king of the Jews, Pilate might elicit self-confessed treason.  Jesus replied, interrogating Pilate if he believed that He was the King of Israel, or if he was simply parroting the Jewish leaders.  Pilate appeared to refuse to get involved in theology and went back to the legal reason for His arrest.  But it was the only legal charge he could make over a 100% righteous person, and, when he was crucified, he ordered that “This is Jesus, the King of the Jews” was nai

Pilate was the supreme Judge of Israel, but he did not recognise truth when it stared him in the face.  He did not recognise Jesus’ identity as the Truth (John 14:6).  Jesus was not guilty of any charge.  Pilate knew that, but he had no courage to release the prisoner.  Pilate feared another riot by the Jews who were insistent that Jesus should die.  Another riot would demonstrate Pilate’s inability to keep order in Israel: not only would he lose his job, he might also lose his head.
 

Pilate, the Roman Governor, had no reason to put Jesus to death.  There was no legal charge to put against Him: and without a legal reason to execute Jesus, the Governor could be stripped of his office, or worse.  The charge that the religious leaders brought was blasphemy (but that was not recognised in Roman law).
 

Pilate was powerful and strong-minded, but he was also weak and afraid.  He feared for his job, his reputation and his life.  His weakest point was fear of punishment by Caesar.  The religious people took full advantage of that, especially when they heard that Jesus had told Pilate that He was the King of the Jews (John 18:37).  They certainly did not want Him as their King; however, to claim to be a king, on Caesar’s territory, was treason – an offence punishable by death.