The Jews did not enter into the palace of Pilate because they wanted to be able to eat the Passover meal. They couldn’t go into Gentile property after 6:00 pm. This is confirmation that the Passover meal had not been eaten yet.

“…it was out of envy that the chief priests had handed Jesus over to him.”
Pilate knew what they were doing and that they set Jesus up, using the political powers to do their dirty work. Pilate was under investigation by Rome for cruelty. He may have been in fear of Rome if he killed an innocent man.

When Pilate asked the people what crime Jesus committed, they never answered his question, they just shouted to crucify him.
Pilate asks again and again trying to get Jesus released, he fails again and again. Finally he gives up and “washes his hands”.
The people answer “Let his blood be on us and on our children.” Curses are called down and the suffering continues to this day.
For more information on the six illegal trials of Jesus see the website.
http://www.philandpatti.com/abiblicalviewofholyweek
(Part 2 and Part 3)