The purpose of the crowd that day was to get him released. Jesus was also a freedom fighter. Jesus was trying to get freedom from the devil. Jesus' way involved gentleness, not swords. Salvation does not come by riot but by surrender.
Salvation is never by violence, it is by faith.
Salvation is not delivered by gun barrels and bullets. Salvation does not come by works or by swords. Salvation comes by yielding your life to your Savior, your God. And they did not know that. Both Jesus and Barabbas wanted to save their people.