The correct answer is not placing your child in front of the evening news, pointing to a criminal and saying, "If you don't clean up your act, that's gonna be you!" What you should do is explain to your child the options the person may have had and what better consequences could have been the result, but not necessarily by watching the news.
No matter how much you understand it's not feasible to anticipate your child, who is considerably younger than you, to have the same comprehension as an adult. The key is "Value." When a child realizes the value of a correct decision the positive reinforcement and encouragement from the results will produce more of the same behavior. Encouraging your child to consider alternatives is the healthy way to gain positive results, which is why corporal punishment and spanking is not the acceptable way to go. What this type of punishment shows is that it is okay to hit, probably producing a child who grows to duplicate this behavior. Your child deserves to be a "thinker" as opposed to someone with a hair trigger temper as a result of not exercising consideration of the outcome.
The die hard truth is, no matter what type of person you are, or the values you display, you can pretty much count on your child continuing the behavior. Parents who steal, lie and abuse, display the behavior as acceptable, no matter what they say can expect reciprocation. This is why the best example may be a silent, yet glowing, example as actions truly do speak louder than words.
Modeling good behavior and explaining to your child what is acceptable behavior is the key to success. Share quality time and don't be afraid to praise your child for a job well-done, if they've done a good job. But this doesn't mean to make a big deal out of something small... that's another subject.
