Closeup of a bloody knife with blood dripping

Prosecutor’s Improper Disparagement of Defense Expert Deemed Harmless

Written on Thursday, April 15th, 2021 by T.C. Kelly
Filed under: Expert Opinions, ExpertWitness, Working with Experts

Thomas Lee Johnson was convicted of first-degree murder. Weeks after a woman was stabbed to death in her home, Johnson told his ex-wife that he had rented a car, driven to the woman’s home, carried a stun gun into the residence, and confronted the woman. Johnson told his former wife that the woman armed herself with a knife and told him to leave. Johnson’s story became confusing at that point, but he said that he panicked in response to the woman’s reaction. He then disposed of the knife and left the state.

Johnson relied on expert witnesses during his trial. On appeal, he argued that the prosecution’s cross-examination of his expert witnesses, and the prosecution’s comment upon the experts during closing argument, was improper. The Colorado Court of Appeals agreed but affirmed the conviction.

Cross-Examination of Clinical Psychologist

Gwen Mitchell, a clinical psychologist, testified about the human response to stress and trauma, including the concept of “fight, flight, or freeze.” She explained that people do not always make a rational evaluation of threatening situations. A mistaken assessment of a threat may lead to the excessive use of force in response to the threat.

Mitchell also testified that after a traumatic event, individuals may suffer from an impairment of memory or may be unwilling to discuss the event. They may also experience dissociative behavior.

On cross-examination, the prosecutor asked Mitchell:

  • if “rational people . . .decapitate women on their apartment floors”;
  • if taking such actions as leaving the state, obtaining false identification, behaving evasively, and hiding the truth from police and family is consistent with an attempt to avoid responsibility;
  • if certain behavior is consistent with “narcissism from the DSM-5 grandiosity”;
  • if the abandonment of parental rights can cause stress and be a sign of narcissism or sociopathy; and
  • if a sexual assault could be the result of stress and if the possibility of a “rape charge” could create further stress.

The defense objected that the questions were irrelevant, inflammatory, or improper. However, the defense used the expert testimony to argue that Johnson’s actions were the result of a primitive response to the perception of a threat. The court of appeals concluded that the prosecutor’s questions were relevant because they were designed to cast doubt on Mitchell’s opinions in favor of the alternative theory that Johnson engaged in premeditated conduct. The prosecution’s hypothetical questions were based on evidence that the jury heard so they were not improper.

The prosecutor certainly walked the line between permissible and impermissible questioning. The court characterized the questioning as “aggressive.” Asking an expert whether rational people “decapitate women on their apartment floors” seems to cross the line from aggressive to inflammatory. With little analysis, the court nevertheless concluded that the questioning did not deprive Johnson of a fair trial.

Cross-Examination of Criminal Investigation Expert

The defense called Joseph Arseneau as an expert in criminal investigations. Arseneau worked for several years as a law enforcement officer before beginning a career that involves litigation support and expert testimony.

The appellate opinion provides little information about Arseneau’s direct testimony. On cross-examination, the prosecutor asked if the evidence that Arseneau reviewed would be “consistent with a sadistic and demeaning sexual cutting” and if it would be “also consistent with [a] brutal, depraved, cold-blooded hacking of a woman.”

The appellate court decided that the questions were not unfairly prejudicial because they explored a theory of the crime as an alternative to Arseneau’s theory. The question, however, was not whether exploring alternative theories was proper, but whether it was prejudicial to do so by using inflammatory language that was likely to stir the passions of the jurors. The court skirted that issue.

Closing Argument

Discussing Arseneau’s expert testimony during its closing argument, the prosecutor:

  • told the jury “that guy is a fraud”;
  • characterized Arseneau’s testimony as the “speculative musings of an overreaching, I suppose, ex-police officer with bare minimal experience, who I submit to you tried to sell himself to us as something . . . he is not”; and
  • argued that “with his bogus web page, [Arseneau was] holding himself out as Colorado P.O.S.T. Certified, with misleading puffery and false swagger, essentially saying anything he can and co-opting the work of others. He reads a book, and he wants to come here and pretend like he’s the author of the book.”

The outrageous nature of the attack on Arseneau was of only slight concern to the appellate court. The court concluded that Arseneau’s nine years of law enforcement experience could fairly be characterized as “minimal” since he was a patrol officer, not a crime scene investigator. Yet expertise can be acquired through study, not just experience, and gaining expertise through study does not make an expert “something . . . he is not.”

Arseneau admitted during his testimony that he was not currently certified by the Peace Officer Standards and Training Board (P.O.S.T.) because P.O.S.T. only certifies current law enforcement officers. Arseneau was certified when he was still working as a law enforcement officer. The appellate court concluded that the failure to indicate on his website that his P.O.S.T. certification was no longer current] provided an evidentiary basis for the prosecutor’s comment that the website was “bogus.” The court relied on that same evidence to excuse the prosecutor’s argument that Arseneau “tried to sell himself to us as something that he is not” and engaged in “misleading puffery.”

The court was more troubled by the prosecutor’s characterization of Arseeau as ““co-opting the work of others,” and as having read a book and “want[ing] to pretend like he’s the author of the book.” The court recognized that the prosecutor had no basis for accusing Arseneau of being a plagiarist. Nor does one “co-opt the work of others” by reading a professional treatise and learning from it. The accusation that Arseneau plagiarized another person’s work was an improper personal attack upon the expert witness.

The court also agreed that the prosecutor crossed the line between fair but aggressive argument and unfair disparagement of an expert witness when he accused Arseneau of testifying “with false swagger, essentially saying anything he can.” While “misleading puffery” went to the content of Arseneau’s website, “false swagger” was a personal attack upon his character. Claiming that Arseneau would say “anything he can” was the equivalent of calling him a “hired gun,” which Colorado precedent forbids.

While the court held that the prosecutor’s personal attack on the expert was improper, the court also held that the evidence against Johnson was so strong that the misconduct could not have influenced the verdict. Characterizing the misconduct as harmless, the court affirmed the judgment.

While the court’s harmless error analysis may be correct, it does nothing to correct the prosecutor’s misconduct or to discourage prosecutors from disparaging experts in the future. Nor does the analysis assure that defendants receive fair trials. Unethical prosecutors who believe in winning at all costs have learned from decisions like Johnson that they can attack defense experts with impunity and without consequence.


About T.C. Kelly

Prior to his retirement, T.C. Kelly handled litigation and appeals in state and federal courts across the Midwest. He focused his practice on criminal defense, personal injury, and employment law. He now writes about legal issues for a variety of publications.

About T.C. Kelly

Prior to his retirement, T.C. Kelly handled litigation and appeals in state and federal courts across the Midwest. He focused his practice on criminal defense, personal injury, and employment law. He now writes about legal issues for a variety of publications.