State v. Singh
In State v. Singh, 259 Conn. 693, 767 A.2d 1214 (2002), the prosecutor also compelled the defendant to characterize the testimony of other witnesses as untruthful, and then emphasized that testimony during closing argument. Id., at 704-705.
The court expressly held that questions that require a defendant to comment on another witness' veracity are improper because they invade the province of the jury, create the risk that the jury may conclude that, in order to acquit the defendant, it must find that the other witness lied, and distort the state's burden of proof. Id., at 707-709.
The court rejected the minority position that an exception should apply when the defendant's testimony is "the opposite of or contradicts the testimony of other witnesses, thereby presenting a basic issue of credibility . . . that cannot be attributed to defects or mistakes in a prior witness' perception or inaccuracy of memory, rather than to lying," because there was no good reason to carve out such an exception. Id., at 710-11.
"The state's objective of 'highlighting' inconsistencies in testimony may be accomplished by other, proper means. Moreover . . . testimony may be in direct conflict for reasons other than a witness' intent to deceive." Id., at 711.
The Singh court also concluded that "closing arguments providing, in essence, that in order to find the defendant not guilty, the jury must find that witnesses had lied, are similarly improper." Id., at 712.
The Court adopted the evidentiary rule, already firmly established in other jurisdictions, that it is improper to ask a witness to comment on another witness' veracity.
The court accordingly prohibited a prosecutor from posing questions that compel a defendant, in response to such questions, to make credibility determinations of the witnesses or to assess the veracity of their testimony. See id.
The Court concluded that the cumulative impact of the prosecutor's improper cross-examination and closing argument, expression of personal views, reference to facts not in evidence and appeal to the passions and prejudices of the jurors so infected the trial with unfairness as to render the defendant's conviction a denial of due process. Id., at 723.