In anticipation of this lack of effective enforcement, the jury might as well assume that the defendant will lie if he is guilty. Even if the jury would believe an innocent defendant wholly and completely, the veracity of the defendant's testimony depends entirely on the jury's prior belief of the defendant's innocence or guilt.
This isn't complete or fully accurate because the defendant isn't acting alone. If the defendant is guilty, the defendant's lawyer faces serious consequences for allowing a guilty defendant lie under oath. And, there are things a defense attorney can do to signal that his client is lying. If these signals are effective, only an innocent defendant would take the stand.
In theory, tying the lawyer's fate to the defendant's perjury is a neat way to allow for a defendant to usefully take the stand. In practice, letting a lying defendant testify creates a series of professional and ethical dilemmas as this Ethics Alarms post illustrates:
The reason the Lying Defendant poses such an ethical conundrum arises from a perfect storm of factors:
Got all that? Put them all together, and this is what a defense attorney faces when his client, who has admitted to his attorney that he is guilty as charged, insists on testifying falsely that he is innocent:
- Anyone accused of a crime has a constitutional right to a defense.
- Because the burden of proof in the United States is on the prosecution to show guilt beyond a reasonable doubt, the job of the defense attorney is to challenge and test the prosecution’s theory of guilt even when the accused is in fact guilty of the crime. The defendant not only has to be found guilty, he or she has to be found guilty for the right reasons, of the correct crime, using legally acquired evidence, with all the defendant’s rights as a citizen respected and protected, in a fair trial.
- A criminal defendant has a the guaranteed right to testify in his or her own defense. No one else does. A lawyer who knowingly allows a civil defendant or any witness to give false testimony can be disciplined and even lose the right to practice law. A lawyer who doesn’t allow a criminal defendant who insists on lying under oath to claim his or her innocence will be disciplined.
- An attorney is absolutely prohibited by the legal profession’s ethics rules from knowingly assisting a client, including a criminal client, in illegal or fraudulent conduct.
- Everything a criminal client tells an attorney in confidence for the purpose of developing a legal defense is privileged, which means it may not be divulged in court or anywhere else. This includes the words, “I am guilty as hell.” The lawyer may not say or do anything that reveals the privileged information.
- Lying under oath in one’s own defense is illegal.
The attorney must allow the defendant to testify, but the attorney cannot “assist” him in testifying. If the attorney refuses to examine the defendant on the stand, which is assisting him, then the attorney signals to the judge and the jury that the defendant is lying. If the attorney acts in a manner that shows that the client is lying about his innocence, than the attorney has revealed the substance of the client’s confidential communication that he is, in fact guilty, a violation of the attorney’s duty of confidentiality, the foundation of the attorney-client relationship.
In other words, whatever a lawyer in this situation does, it will violate the ethics rules, the rights of the defendant, or the United States Constitution.Given the original perjury-has-no-force incentive problem, the simplest solution would be to outlaw taking the stand in your own defense. This sounds like prohibiting your right to defend yourself, but defending yourself amounts to much more than taking the stand at your own trial. And, it might be that the best way to defend yourself is to submit to a system that doesn't allow you to speak directly at your trial. Let the evidence and witnesses speak, and if there's a rebuttal to be issued, the defense attorney can make this case. In other words, submit completely to a system of legal expertise.
This tension between lawyer and client reminds me of a really interesting paper by Rob Fleck and Andy Hanssen entitled, On the Benefits of Legal Expertise: Adjudication in Ancient Athens (pdf). Rob and Andy discuss a quirky legal system in Ancient Athens in which legal expertise was banned, and they develop a model to evaluate the costs and benefits of having a system of professional representation. I'm not sure where the guilty, lying client falls in their model, but it is related. And, it is an interesting thought experiment unto itself.