An excerpt from a recent post on Bart Ehrman’s Blog:
The reasons Jesus would not have been one of these for whom burial would be allowed are the ones that I have given extensively over the course of the past three weeks. To sum it up, not only during war but also in times of (relative) peace the Romans publicly humiliated and tortured to death enemies of state precisely in order to keep the peace. Jesus was condemned not for blasphemy, not for cleansing the temple, not for irritating the Sadducees, not for bad-mouthing the Pharisees, not for … well, not for anything but one thing. He was crucified for calling himself the King of the Jews.
Only Romans could appoint the King. If Jesus thought he himself was going to be the King, for the Romans this would have been a declaration of war (since he would have to usurp their power and authority to have himself installed as king) (I’m talking about how Romans would have interpreted Jesus’ claim to be king, not what he himself may have meant by it). They may have found it astounding, if not pathetic, that this unknown peasant from the rural hinterlands would be imagining that he could overthrow Roman rule in Judea. But Romans didn’t much care if someone was a megalomaniac, a feasible charismatic preacher, or a bona-fide soldier in arms. If the person declared “war” on Rome – which a claim to being the King amounted to – the Romans knew how to deal with him. He would be publicly tortured and humiliated, left to rot on a cross so everyone could see what happens to someone who thinks he can cross the power of Rome. There was no mercy and no reprieve. And there was no decent burial, precisely because there was no mercy or reprieve in cases such as this.
After the point was made – after time, the elements, and the scavengers had done their work – the body could be dumped into some kind of pit or common grave. But not until the humiliation and the punishment were complete. Yes, it’s true that in Jesus’ day, the country was not in armed rebellion against Rome. There was a general peace. But this is the very reason *why* there was peace. Would-be offenders – insurrectionists, political enemies, guerilla warriors, rival kings, enemies of the state – were brought face to face with the power of Rome in a very gruesome way, and most people, who for as a rule preferred very much not to be food for the birds and dogs, stayed in line as a result.
In sum, even if Josephus is stating a general practice among Jews (I’m not sure we can trust that he is. But even if he is), it is not a practice that applied to times of war or threats of war. As we have seen repeatedly in the past three weeks, it did not apply to enemies of the state. Jesus was an enemy of the state, crucified for calling himself King of the Jews.
—New Testament scholar Bart Ehrman