A lawyer in Wisconsin has a duty of candor under Supreme Court Rules 20: 1.2, 20:1.6, 20: 3.3, 20: 4.1 and 20: 8.4 (formerly DR 7-102(A) . Rule 20: 4.1 (a) (1) (Truthfulness In Statements to Others) states that “in the course of representing a client, a lawyer shall not knowingly make a false statement of fact or law to a third person.” This means an attorney has a duty to zealously represent a client and guard their confidences. However, they also have a duty to the court not to present evidence that they know is false, fraudulent, or perjured, whether it’s coming from the defendant or a witness whom the lawyer knows intends to lie. Additionally, Rule 20: 1.3 requires a lawyer to “act with reasonable diligence and promptness in representing a client.” The official comment to this rule expands this concept to include “commitment and dedication to the interests of the client and with zeal in advocacy upon the client’s behalf.” Rule 20: 1.3 ABA Comment 
In practice, these restrictions are far from clear.
A lawyer may not knowingly lie, but has no obligation to find the the truth or to draw logical inferences from what he or she knows. In a criminal case, a lawyer usually is not at the scene of the crime. Therefore, the lawyer can maintain that she doesn’t know for sure what happened–allowing her to argue the client’s version of events. In fact, “zealous advocacy” requires a lawyer to argue his client’s version of events–regardless of what others may believe. This is why in criminal practice, many criminal defense lawyers never ask their client if they are guilty or innocent of a charge.
The age old question presented to students in law school concerns a client who simultaneously confesses to a crime and insists on testifying that he is innocent. This presents a thinking criminal defense attorney of constitutional dimensions since:
- anyone accused of a crime has a constitutional right to a defense.
- 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. This means a lawyer for the defendant in a criminal proceeding, should defend the proceeding as to require that every element of the case be established. SCR 20: 3.1 (b)
- a criminal defendant is guaranteed the right to testify in his or her own defense. No one else has that that federal constitutional right which is the Supreme law in America. The ethical rules tell a lawyer that the ethical rules are subordinate to the lawyers constitutional obligations. SCR 20:3.1 ABA Comment .
BUT an attorney is absolutely prohibited by the legal ethics rules mentioned from knowingly assisting a client, including a criminal client, in illegal or fraudulent conduct. Including lying on the witness stand. However, how does a lawyer know with absolute certainty that a client is going to lie on the witness stand? How does a lawyer know any fact of a case with certainty? In this time when false confessions are made to police or police misconduct in obtaining confessions, it cannot be presumed that simply because a defendant says something different than a confession means they are lying.
Even if a lawyer somehow knows, she is not allowed to report this to the court. When a defendant informs counsel of the intention to testify falsely, the attorney’s first duty shall be to attempt to dissuade the client from the unlawful course of conduct. The attorney should then consider moving to withdraw from the case. If the motion to withdraw is denied and the defendant insists in committing perjury, counsel should proceed with the narrative form of questioning, advising the defendant beforehand of what that entails and informing opposing counsel and the circuit court of the change of questioning style prior to use of the narrative. But this can only be done if the lawyer knows a client is going to lie on the witness stand. State v. McDowell, 2004 WI 70, 272 Wis. 2d 488, 681 N.W.2d 500.
Finally, if a lawyer finds that his client has perpetrated a fraud on a court–i.e., told a lie in court–the rules say the lawyer should inform the court, unless the information was told to him in confidence or secret. But, of course, just about everything that a client ever tells a lawyer is a secret or a confidence.
It should be noted prosecutors can run into ethical difficulties as well. For instance, federal prosecutor in Brooklyn was excoriated by name by the Second Circuit in 1982 in United States v. Jacobson, 691 F.2d 110 (2d Cir. 1982). for “serious inconsistencies between the government’s brief and the actual record before the grand jury,” along with other misrepresentations actually made by the prosecutor during oral argument before the Second Circuit itself. Particularly troubling to the court was the fact that the misrepresentations related to grand jury transcripts to which the defense had no access. Said the court, “[W]e expect those government counsel involved to take heed of the seriousness with which we view inaccurate representations of fact, and those who supervise them to take affirmative steps to prevent a recurrence.” Id. at 115-116 It was publicly reported that the prosecutor at issue was resultantly placed under intense supervision by the U.S. Attorney.
Likewise, in Matter of Stuart, 803 N.Y.S.2d 577 (2d dept. 2005) the Second department imposed a three-year suspension on an assistant district attorney for falsely telling the trial judge, in response to his constitutional duty to turn over evidence of a defendant’s innocence, the prosecutor maintained he had no knowledge as to the whereabouts of a certain witness despite several unsuccessful attempts to locate her. In fact, the prosecutor had himself met with the witness at her place of employment five days earlier. The prosecutor’s defense to the charge of professional misconduct included character letters from two judges, testimony about his service to his churches and the U.S. Army JAG Corps Reserve, and his 12-year tenure as a prosecutor with 70 felony trials under his belt, and still it could not save him from himself. See also, The Myth of Prosecutorial Accountability After Connick v. Thompson: Why Existing Professional Responsibility Measures Cannot Protect Against Prosecutorial Misconduct (man who spent fourteen years on death row because prosecutors withheld exculpatory blood evidence from his defense attorneys.)
This article makes the sad comment that in reality, prosecutors have rarely been subjected to disciplinary action by state bar authorities.