Two other criminals were also led away to be executed with him. So when they came to the place that is called “The Skull,” they crucified him there, along with the criminals, one on his right and one on his left. But Jesus said, “Father, forgive them, for they don’t know what they are doing.” Then they threw dice to divide his clothes. The people also stood there watching, but the leaders ridiculed him, saying, “He saved others. Let him save himself if he is the Christ of God, his chosen one!” The soldiers also mocked him, coming up and offering him sour wine, and saying, “If you are the king of the Jews, save yourself!” There was also an inscription over him, “This is the king of the Jews.”
One of the criminals who was hanging there railed at him, saying, "Aren't you the Christ? Save yourself and us!" But the other rebuked him, saying, "Don't you fear God, since you are under the same sentence of condemnation? And we rightly so, for we are getting what we deserve for what we did, but this man has done nothing wrong." Then he said, "Jesus, remember me when you come into your Kingdom" And Jesus said to me, "I tell you the truth, today you will be with me in paradise." (Luke 23:32-43)
Criminals, thieves, robbers, etc. It conjures the idea of a couple of no-good scoundrels - the dregs of society. Have you ever stopped to think about these two guys? A couple of obvious questions come to mind right away:
a) would Rome crucify people for mere theft? Let's even say that it was serious theft -- crucifixion wasn't the commonplace way of killing people in ancient Rome...would that kind of punishment really have fit the crime?
b) How do they know who he is? Read carefully what the two men say. The first one knows, at least at some level, what "the Christ" (or 'Messiah' in some translations) is supposed to be able to do. He says, "save yourself and us!" Now, he could have just been mimicking what the religious leaders were jeering...but the response of the second criminal indicates that it's more than that. "Don't you fear God?" This suggests that the two men were Jews - it's not just some random God that this man is referring to. Also - the second criminal knows that Jesus has done nothing wrong - AND he knows that Jesus is who he says he is and what that means. He knows the Jesus has a kingdom and that He's going ENTER it, AFTER dying. To me, this is the most convincing line that these men knew who Jesus was and what His claims were.
The most likely scenario for who these men were, and why they would end up being crucified WITH Jesus, is that they were zealots, or insurrectionists, which is essentially the same charge against Jesus (don't forget, Barabbas, who Jesus exchanged fates with, was also in prison for insurrection, Luke 23:19). Furthermore, they were likely Jewish Zealots. Jesus would have been familiar with a group like this because one of his own disciples, Simon, came from the zealot movement.