Matthew 27:25 And the whole people said in reply, "His blood be upon us and upon our children."
He people have acceptd the responsibility for Jesus' death. Verbally anyway. They really have no idea what they have taken responsibility for. They had been encouraged by the high priests to ask for Barabbas to be free and Jesus to be crucified.
Still today, we deny Jesus the way Peter did. Each time we knowingly sin or willingly put outlives into bad situations, we deny Jesus. We put him on the cross.