Background
Matthew Zick Krob was charged with multiple felonies arising from two domestic incidents with his then-wife. In November 2022, police responded to a 911 call reporting a physical domestic dispute. The victim reported that Krob had assaulted her and taken her phone. She subsequently reported that Krob had also assaulted her approximately one year earlier. Krob was ultimately charged with two counts each of sexual assault and unlawful sexual contact, two counts of assault, and one count of obstruction of telephone service.
At trial, Krob’s defense strategy was to argue that the victim had fabricated all allegations to gain advantage in pending divorce proceedings. A jury found Krob guilty on all counts, and the trial court sentenced him to twelve years to life in the Department of Corrections. Krob appealed, raising four main contentions: (1) improper admission of domestic violence expert testimony; (2) impermissible leading questions on direct examination; (3) prosecutorial misconduct during closing arguments; and (4) erroneous jury instructions on reasonable doubt.
The Court’s Holding
The Colorado Court of Appeals affirmed Krob’s conviction in full. On the expert testimony issue, the court found no reversible error in admitting testimony from Jennifer Walker, a domestic violence expert. Although Krob challenged Walker’s qualifications and the fit of her testimony to the case facts, he did not challenge the underlying scientific reliability of domestic violence expert testimony—an omission that excused the trial court from making specific reliability findings on the record. The court found Walker’s testimony about trauma’s effects on victim memory and the dynamics of isolation and economic abuse in domestic violence relationships both relevant and helpful to the jury.
On leading questions, the court determined the trial court acted within its broad discretion in allowing the prosecutor to ask leading questions on direct examination. The prosecutor used these questions to manage the victim’s tendency to give non-responsive answers, a valid use of leading questions under Colorado Rules of Evidence 611(c). Regarding prosecutorial misconduct, the court found the prosecutor’s statement that the victim had nothing to gain in a criminal trial (as opposed to a divorce proceeding) was a fair response to the defense theory and did not misrepresent the law or facts. Finally, on jury instructions, the court held that using the 2022 model jury instructions—which omitted the 2023 addition stating that reasonable doubt “can be based on the evidence presented or the lack of evidence presented”—did not constitute structural error in violation of due process.
Key Takeaways
- Expert testimony about domestic violence victim behavior, memory, and relationship dynamics is admissible when properly limited in scope and qualified by sufficient experience.
- Trial courts retain substantial discretion to permit leading questions on direct examination when necessary to manage witness testimony, and appellate courts will only reverse for clear abuse of discretion.
- A prosecutor’s argument distinguishing a criminal trial from a civil divorce proceeding does not constitute misconduct, particularly when responsive to the defense’s divorce-motive theory.
- Omitting the phrase about reasonable doubt being based on “the lack of evidence” from jury instructions does not rise to structural error, though courts may voluntarily adopt updated model instructions.
Why It Matters
This decision provides important guidance on the admissibility of domestic violence expert testimony, particularly regarding how trauma affects victim memory and recollection. Since victims of domestic violence may struggle to recall events in chronological order or remember all details consistently, courts can rely on expert testimony to help juries understand these behaviors as typical trauma responses rather than indicators of fabrication. The case confirms that such testimony—when appropriately tailored and not permitted to comment directly on credibility—remains a vital tool in domestic violence prosecutions.
The decision also reinforces broad judicial discretion in managing trial procedure and prosecutor latitude in closing arguments. For defense practitioners, the case illustrates the difficulty of preserving appellate issues when objections are not made with sufficient specificity at trial. For prosecutors and victim advocates, the decision provides reassurance that established evidentiary principles supporting domestic violence cases will remain available even as jury instructions evolve.