Can prosecutors bolster witness credibility before it's attacked? State v. Perez Explained

In State v. Perez, the Utah Court of Appeals addressed a fundamental evidentiary issue that frequently arises in criminal trials: when can prosecutors introduce evidence to support a witness’s credibility?

Background and Facts

Defendant Raymond Perez was convicted of drug distribution charges based on two transactions with confidential informant Adam Black. The State introduced extensive evidence about Black’s past success as an informant, including testimony that his information had led to multiple arrests and convictions, and that he had helped capture a fugitive wanted in three states. This evidence was presented both in the prosecutor’s opening statement and through direct examination of officers, all before the defense attacked Black’s credibility.

Key Legal Issues

The central issue was whether the State violated Utah Rule of Evidence 608 by bolstering Black’s credibility before the defense attacked it. Rule 608(a) specifically provides that “evidence of truthful character is admissible only after the character of the witness for truthfulness has been attacked.” The court also had to determine whether any error was prejudicial under the plain error doctrine.

Court’s Analysis and Holding

The Court of Appeals found plain error. The court rejected the State’s argument that anticipatory rebuttal was permissible because the defense later attacked Black’s credibility in opening statement. The court emphasized that allowing such anticipatory bolstering creates a circular problem—if prosecutors bolster credibility in opening statements, defendants may feel compelled to attack it, which prosecutors could then claim justified their earlier bolstering.

However, the court found prejudice only as to the first transaction, where Black’s testimony about the actual drug exchange was uncorroborated due to surveillance limitations and equipment failures. The second transaction was sufficiently corroborated by officer testimony.

Practice Implications

This decision reinforces that credibility evidence must be properly timed. Prosecutors cannot introduce evidence about a witness’s reliability or past successes until the defense first attacks the witness’s character for truthfulness. Defense counsel should object immediately when prosecutors attempt to bolster witness credibility prematurely, as this violation of Rule 608 may constitute reversible error when the witness’s testimony is crucial and uncorroborated.