Can defendants use DNA evidence to suggest alternative sexual partners in rape cases? State v. Beverly Explained

In State v. Beverly, the Utah Supreme Court addressed the complex intersection of Utah’s rape shield law and DNA evidence in sexual assault prosecutions, providing important guidance for practitioners handling similar cases.

Background and Facts

Mark Beverly was convicted of rape and forcible sexual abuse of his estranged wife. After being separated for two years without physical intimacy, Beverly became enraged one night, entered his wife’s bedroom, slammed the door, and demanded sex. Despite her repeated refusals and crying, he forced her to engage in sexual conduct. DNA analysis of the victim’s rape kit revealed a major profile matching Beverly and a minor profile that could not be definitively identified as male or female DNA.

Key Legal Issues

The central issue was whether Beverly could use the minor DNA profile to suggest his wife had sexual contact with another person, either to impeach her credibility or to show an alternative source for her physical injuries. The trial court excluded this evidence under Utah Rules of Evidence 412 (rape shield law) and Rule 403 (unfair prejudice).

Court’s Analysis and Holding

The Utah Supreme Court affirmed the exclusion on two grounds. First, using DNA evidence solely to impeach a victim’s credibility about sexual behavior violates Rule 412’s prohibition against admitting evidence of a victim’s sexual conduct for character purposes. The court emphasized that Rule 412 contains “no exception for the admission of past sexual conduct to impeach witnesses.”

Second, even if the evidence qualified under Rule 412(b)(1)’s alternative source exception, it failed the Rule 403 balancing test. The court noted the evidence had minimal probative value because the forensic scientist could not determine whether the minor profile was from another male or simply the victim’s own vaginal cells from the collection process. This uncertainty meant the defendant was asking the jury to speculate about sexual conduct that could not be proven.

Practice Implications

This decision reinforces that Rule 412’s protections are robust and that alternative source evidence must clear both the rape shield law and the unfair prejudice analysis. Practitioners should ensure that DNA evidence offered as alternative source evidence has sufficient scientific certainty and probative value to survive Rule 403 scrutiny. The court’s analysis in Beverly demonstrates that speculative DNA evidence with uncertain origins will likely be excluded as more prejudicial than probative.