It depends what you mean by karma exactly. Do I think that there is a intervening cosmic force that ensures that good deeds are rewarded and bad deeds punished? No I don't believe that. However, a person who does wicked things will quite naturally be worst off, then a virtuous acting individual. That comes as a consequence of the fact that doing wrong, harms the doer even more so then the victim. To paraphrase Plato, The better man can not be harmed by the worse man. Of course the better man can be maimed, robbed and murdered by the worst man; however these are not true harms. Imagine Jesus on the cross. Can he be said to have been harmed or lessened by mankind? Or is the man named Jesus executed, but his essence as a person left unmarred? The same can be asked about Gandhi or Martin Luther King. These men meet their death but they can not be said to have been harmed. They are murdered, but who they were principally is left untouched. Furthermore, in killing such men, the murderers do themselves a disservice. The world is better for the existence of Jesus, Gandhi and King; a world without them is worst off. To rid the world of such men, is ultimately to the killers detriment; as none are more in need of these figures positive influence then those who is vile enough to commit murder. The murderer ends up killing that very thing he needed to observe most. He is bound to be a worst man now. That is a karma of sorts.