I got into criminal defense after participating in the criminal litigation section of the University of Nebraska College of Law. I was an assistant to the county attorney who prosecuted criminal defendants. I routinely saw unprepared defense attorneys beg and plead for good deals from the county attorney's office and many were unable to get very good deals because they were not prepared to show the county attorney why they had a weak case if it went to trial. I noticed the most effective defense attorneys were those that were not only prepared by knowing the facts that police had provided the county attorney with, but also a command of the facts that s/he had obtained through their own investigation.
I have tried to pattern my practice after this experience. The best defense is being thoroughly prepared, knowing the strengths and weaknesses of your case, and being able to clearly articulate to the prosecutor why if the case went to trial, they will lose. Or it is convincing the judge/jury why there is reasonable doubt, thereby justifying an acquittal.
The greatest victory is not winning a case, however. It is helping others to see and internalize their God-given potential so their behavior is no longer guided by the legal system--but rather their inner compass. It is then that our social laws become irrelevant.