Pilate told the people that they could choose to spare the life of either a murderer named Barabbas or Jesus of Nazareth, and they chose Barabbas. Given the same choice, Jesus, of course, would have chosen to spare Barabbas too.
To understand the reason in each case would be to understand much of what the New Testament means by saying that Jesus is the Savior, and much of what it means too by saying that, by and large, people are in bad need of being saved.
Mark 15:6-15
~originally published in Peculiar Treasures and later in Beyond Words