Science, Pseudoscience, and the Law

PhACT’s September 2009 meeting was led by Dr. Lewis Mifsud, a physicist and electrical engineer whose topic was Science, Pseudoscience, and the Law. Science is used in laboratories, hospitals, and schools, among many other places. One surprising, yet appropriate, place is in court. Science is known for being accurate, precise, and reasonable. Because of this the use of science to present evidence has undergone changes in the courtroom.
The first use of science in court was in 1923. The results of a lie detector were presented as evidence, but were not accepted by the judge. Back then, if the scientific community did not agree with the scientific evidence, the evidence was not accepted. This continued for 52 years until federal rules of scientific evidence were defined.
The necessity for regulation of federal standards was not only needed for proven scientific facts presented as evidence, but also for the dismissal of false or misleading facts presented as science, known as pseudoscience. Pseudoscience is a methodology, belief, or practice that is claimed to be scientific, or that is made to appear to be scientific, but which does not adhere to an appropriate scientific methodology, lacks supporting evidence or plausibility, or otherwise lacks scientific status, for example, the 1993, "Determination of Fire Origin and Cause." This evidence argued facts that were common myths believed by many. The ideas that fire seeks oxygen, blistering of concrete is proof of the presence of flammable liquid, and collapsed furniture springs are an indication of an accelerated fire, were presented in courts as scientific facts. Evidence or pseudo sciences like these led to many unfair rulings in insurance claim suits and even arson convictions.
Pseudoscience was allowed to be presented in court because of the 1975 Federal Rule of Evidence 702. The rule stated that there was science involved in everything, so anything could be used as science and that the evidence had to be part of the testimony of an expert in the field of the scientific evidence, whether that expert is a rocket scientist, chemist, or even a plumber. The problem with the rule was that it defined an expert to be pretty much anyone.
It was not till the 1993 Daubert case, where the plaintiffs claimed the drug Bendectin was the cause of limb reduction defects. The suit went to district court where the plaintiffs tried using rule 702 of the federal rules of evidence, but lost the case based on a well-credentialed expert with published material citing the 1923 general acceptance rule. This was a case of an expert’s testimony versus another expert’s testimony which was the same result of scientific eidence before rule 702. The scientific community in the form of published material supported the defense. The plaintiffs appealed the ruling, and responded with eight experts reanalyzing the published material presented before, but it was not till the case was taken to the Supreme Court where they realized some regulation needed to be in effect. The United States Supreme Court overruled the 1923 general acceptance rule and replaced rule 702.
The replacement of rule 702 added four validation criteria for scientific evidence to be presented in court. The first was testability which meant that the results had to be predictable, or repeatable. The second criterion was the knowledge of potential error. With this knowledge the accuracy of necessary results was determined. Thirdly, peer review was implemented so that the other side of the case was able to conduct their own tests. The last criterion was that a general acceptance could only contribute to the evidence, and would not have a negative effect if not. The Daubert’s criteria demanded accuracy and precision in measurements and results, error rates in products and processes, and testing to prove or falsify results presented as evidence.
The evolution of scientific evidence in the courtroom shows that as we learn more and more about our universe, older theories once thought to be true are proven to be false. This is why regulation was needed to ensure a fair trial.