The gospels do portray Pilate as repeatly finding Jesus innocent, but due to the pressure of the crowd, Pilate does sentence Jesus to death.
MK 15: 6-15 "At every Passover Festival Pilate was in the habit of setting free any one prisoner the people asked for. At that time a man named Barabbas was in prison with the rebels who had committed murder in the riot. When the crowd gathered and began to ask Pilate for the usual favor, he asked them, `Do you want me to set free for you the king of the Jews?' He knew very well that the chief priests had handed Jesus over to him because they were jealous. But the chief priests stirred up the crowd to ask, instead, that Pilate set Barabbas free for them. Pilate spoke again to the crowd, `What, then, do you want me to do with the one you call the king of the Jews?' They shouted back `Crucify him!' `But what crime has he committed?' Pilate asked. They chouted all the louder, `Crucify him!' Pilate wanted to please the crowd, so he set Barabbas free for them. Then he had Jesus whipped and handed him over to be crucified."
Comment: Pilate is not in a very strong position at this time. As governor, he was a political appointee, and the person who had appointed him governor had just been arrested and executed for plotting against Caesar: instant death. Pilate, as a political crony of his patron, would have been under some amount of suspicion himself. In John's gospel, the Jews play on Pilate's fears: "If you set him free, that means that your are not the Emperor's friend! Anyone who claims to be a king is a rebel against the Emperor [= Caesar]! (JH 19:12)."