Forensic science is on the border between science and the law – forensic scientists try to solve problems that are related to the law, through science.
There can be stark differences in the way scientists and lawyers use the same terms, and this has the potential to cause confusion and misunderstandings. To further complicate the issue, some terms that do have a commonly shared meaning in reports or testimony, may be understood differently by jury members or other members of the general public.
Jurists and the general public are seeking clear yes/no answers in the courtroom, but science does not usually lend itself to that type of language.
“I don’t know” has long been the catchphrase of the academic scientist. The ideal situation would allow for lab analysts to follow suit, and for lawyers to be satisfied when the lab reports results as “inconclusive” rather than pushing for the scientist to make a guess, or draw a firm conclusion with limited confidence. Additional problems arise because a scientist’s training requires that results be delivered in the context of estimates of error and other considerations.
Lessening the pressure on analysts to come to a firm conclusion on the evidence before them would require a dramatic cultural change.
Because juries place such trust in the opinions of experts, both legal professionals and forensic experts need to use clear language that explains the limitations of the conclusions and the statistical significance of the results, if applicable.
Therefore, it is incumbent upon attorneys to understand the limitations of the analysis and of the interpretation of the evidence.
Some types of forensic evidence do not lend themselves to the use of statistics. In those cases, it is important to point out to a judge or jury that the evidence cannot be evaluated with statistics, and for them to take that fact into account when weighing the value of that evidence.
When the evidence presented does, however, lend itself to statistical analysis, then it is important to make sure the right language is used so that the jury or judge understands the significance of any results presented.
For example, a hair found at the scene may be called “consistent with the hair of the defendant”. That statement carries a tremendous deal of weight with a jury. But if on cross examination the defense counsel asks the expert to qualify that statement by giving an idea of how many individuals in a population would have hair consistent with the sample, the judge and jury will have a better context in which to qualify the expert’s opinion.
It is also important for an attorney to understand when a forensic methodology that’s amenable to statistical analysis is not backed up by statistics, and to question that missing information.
Language can be problematic when less experienced analysts face balancing technical language with terms that can be easily understood by the jury and judge. It takes practice to know how much terminology is too much and how much is actually necessary to ensure accuracy.
In addition, novice analysts have a hard time finding a good balance of confidence and modesty in front of a jury or fact finder. It may be hard for analysts not to become defensive when pressed on their opinions, or to stand firm on their opinions when pressured to back down.
The appropriate language in both these situations comes with experience and confidence that cannot necessarily be taught. Learn more about language in the section entitled Ethical Differences.