Lay opinion rule in evidence

¶ … Roland William Dube robbed a federal-insured bank. When brought to trial in the case United States of America v. Roland William Dube in 1975, he did not deny that he had robbed the bank. Instead, he attempted to show that he was insane at the time of the offense, and therefore not criminally responsible for his actions. The prosecution did not bring in expert testimony to refute Dube's claims, but instead relied upon the testimony of three lay witnesses -- two of the bank tellers and Dube's accomplice -- in order to refute his claims of insanity.

Dube's motion of acquittal was denied, on the grounds that the prosecution had no obligation to use expert witnesses to refute the defendant's insanity claim. The question of sanity was for the jury to decide. If the prosecution deemed it reasonable to use lay witnesses rather than expert, that was their prerogative. As such, the jury was within its bounds when it convicted Dube.

Role of Lay Testimony

In this trial, the defense attempted to build a case with expert testimony; the prosecution relied on lay testimony. Adding an element of complexity was that the expert testimony was based on lay descriptions of behavior. The expert testimony consisted of two psychiatrist analyses that Dube was schizophrenic. These were based on brief interviews with Dube, several months after the crime and right before the trial.

The use of lay testimony is this case was to refute the claims made by the prosecution. The prosecution could have conducted its own psychiatric evaluation of Mr. Dube, but chose to go with lay witnesses because they felt their case would be stronger. One is that the lay witnesses were present during the crime, and could attest to the defendant's behavior during the incident much more accurately than could a psychiatrist operating months after the fact. The prosecution believed the first-hand lay testimony of the bank tellers would resonate more strongly than the expert testimony. The testimony of both expert and lay witnesses is subject to jury evaluate for both weight and credibility. The prosecution clearly believed that the lay testimony would be given greater weight. Clearly, the fact that the psychiatrists made their diagnosis so long after the incident, from such short interview times, and in a situation where insanity was Dube's only hope of avoiding conviction, was something that the prosecutors knew would weight in the jury's minds. The psychiatrists' opinions would likely not hold sufficient weight to create reasonable doubt of sanity in such a circumstance. The use of the expert testimony in this case was allowed because the experts did not need to have personal knowledge. However, the prosecution knew that in light of the rather shoddy "expert" work that went into the diagnosis, personal knowledge was going to be viewed by the jury as more credible.

There are some potential problems with the use of lay testimony. One is that lay testimony is always subject to interpretation. Lay witnesses are testifying about personal sensory experiences (Nordberg, 2007). All such experiences are interpretative to some extent. Another potential problem with the use of lay testimony is that it may not be interpreted as credible relative to expert testimony. Clearly in the Dube case it was, but this is a substantial risk for a legal team to take. Expert witnesses have credibility that stems from advanced training and perceived objectivity. Lay witnesses can merely interpret their own experiences. This brings us to another weakness of lay testimony -- it can only reflect personal experience. Whereas experts do not need to have direct involvement in the case events, lay witnesses do. They are therefore unable to comment on anything other than what they saw directly. The prosecution in the Dube case relied on witnesses to the crime, but had the defense entered substantial evidence of insanity outside of the actual robbery, the prosecution would have required more than just lay testimony to refute it.