Lawyers don't seem to be interested in justice. The truth is that most lawyers are not supposed to be interested in justice. Lawyers are only spokespersons for their clients and nothing more. Lawyers do not have to make moral judgments about the actions or beliefs of their clients. It is not their job to do so.
Lawyers are responsible to execute their clients' cases in the most effective way possible.
If the argument is nothing more than a lie, then the lawyer must present that lie in the most effective way possible. Jerry Spence and most other defense lawyers do not want to know whether or not their clients have committed the double homicide. A lawyer attacks or defends, for a client, to the best of his or her ability under the law. The judicial system is designed that way for a reason. The adversative trial system gives clients a chance to present their side of the story, no matter how convoluted and far from the truth it may be.