A criminal defense attorney knows the damaging effect that inflammatory or overly prejudicial evidence may have on a jury. Indeed, there’s an evidentiary objection that can be made on that basis, where the prejudicial aspect of a proposed submission outweighs its probative value.
Yet according to a recent article, jurors in a criminal trial may not even realize that much of the information they are hearing might be biased, unreliable and/or inaccurate. Specifically, the article was addressing forensic evidence.
The problem may start with how forensic evidence is processed: Prosecutors may tell lab workers the results they are expecting up front. Another concern is that there is no federal regulation of forensic analysis techniques. Medical diagnostic tests, in contrast, are subject to governmental agency testing. Yet the same is not true of forensic analysis.
According to a 2009 study by the National Academy of Sciences, only DNA analysis had even a suggestion of consistency and the scientific method. Fingerprint and hair analysis methods were not uniform, nor were the analytical techniques applied to bite-marks, ballistics or handwriting analyses.
Without uniform regulation, a judge in a criminal trial may be forced to decipher between competing expert opinions regarding the reliability of forensic evidence techniques. According to one commentator, that battle-of-the-experts forces judges to act as amateur scientists, which may be beyond the scope of their legal training.
The commentator also believes that a judge shouldn’t entrust the jury to weigh the credibility of forensic evidence. Given popular crime shows like “CSI,” individuals may have a preconceived bias in favor of forensic evidence. An attorney that focuses on criminal defense can work with experts and other professionals to educate jurors about the credibility concerns involving non-DNA forensic evidence.
Source: Slate, "Forensic Science Isn’t Science," Mark Joseph Stern, June 11, 1014