I lol'd at the subject line because my dog's name is Karma and he's sitting right next to me. So yes, Karma DOES exist. LOL

On the topic, however, I really feel the answer to the OPs question is do YOU BELIEVE it exists? It all comes down to your personal beliefs, values, morals and ethics. Why is it so important to classify a behavior as good/bad based on whether you will be caught or not?

If YOU believe its okay to steal, lie, cheat, commit murder, etc, knowing there will not be consequences to pay, or not caring about those consequences, then thats your personal belief and nobody can change that or tell you its right or wrong.