Matthew 27:44 (also Mark 15:32)
In the same way the robbers who were crucified with him also heaped insults on him.
One of the criminals who hung there hurled insults at him: "Aren't you the Christ? Save yourself and us!"
But the other criminal rebuked him. "Don't you fear God," he said, "since you are under the same sentence?
It's possible that one robber started out mocking Jesus and then changed his mind. Both robbers would have heard Jesus forgiving his persecutors (Lk 23:33-34) and then observed him on the cross. The manner of Jesus' death impressed a centurion and the crowds (Lk 23:46-48), and it may have impressed the robber as well.