Appellate Courts Should Resist the Temptation to Conduct Their Own Independent Research on Scientific Issues

Article excerpt

When science has the potential to affect nearly every type of case in the judicial system, and where access to information is greater than ever before, courts increasingly confront the question of whether they should conduct independent research into the reliability of proffered scientific theories and techniques. In this article, I focus on the appellate perspective. My thesis is simple: regardless of what trial courts may do, appellate courts should resist the temptation to conduct their own independent research of scientific literature.1

Three reasons for this are apparent. First, gathering scientific literature on a subject is essentially a fact-finding mission-a task alien to appellate decision making. second, appellate courts lack critical tools available at the trial level for determining truth and for assessing the credibility and reliability of evidence. Finally, reasonable alternatives to independent research exist.

Appellate court's role

Traditionally, trial courts are assigned the role of finding facts.2 Even when the evidence before a trial judge consists solely of documents, the trial judge is still generally entitled to deference as the factfmder because "with experience in fulfilling that role comes expertise."3 Appellate courts are not generally in the business of making factual determinations; doing so brings them into unfamiliar territory.4 Of course, appellate courts are in the business of evaluating the evidence presented in a trial record, but independent research goes beyond reviewing materials submitted.5 No matter how careful the investigation, there is always a risk that the appellate court will mistakenly rely upon spurious materials, or that the research will fail to uncover sources that are crucial to determining the reliability of the scientific theory or technique.6

Critical trial-level tools

Appellate courts lack some critical tools available at the trial level for arriving at an accurate determination: live testimony and cross-examination. Experts practicing in the field may have knowledge and experience beyond what is reflected in the available scientific literature.7 And adverse parties can test the credibility and reliability of proffered literature by subjecting the expert witness to "the greatest legal engine ever invented for the discovery of truth"8-cross-examination. The trial judge himself may participate in the process by asking questions of the live witnesses.9 However, these events can occur only at the trial level.

As a general rule, appellate courts do not hear live testimony, so literature considered for the first time at the appellate level is not subject to live comment by practicing experts and cannot be tested in the crucible of the adversarial system. Internet sources have come under criticism for their potential unreliability,10 and one of the core criticisms against the use of such sources by appellate courts is that doing so usurps the trial court's fact-finding function: "When an appellate court goes outside the record to determine case facts ... it ignores its function as a court of review, and it substitutes its own questionable research results for evidence that should have been tested in the trial court for credibility, reliability, accuracy, and trustworthiness."11 This criticism applies with full force to the use of outside-the-record texts and treatises, regardless of the medium in which they are found.


Uniformity of application is desirable in the scientific evidence context. Trial courts should not have to reinvent the wheel regarding the validity or reliability of a well-established scientific theory or technique every time evidence invoking that theory or technique is proffered.12 Appellate courts can promote the efficient use of judicial resources, provide guidance to trial courts, and help ensure uniformity of decision making by establishing the validity and reliability of various scientific theories and techniques as a matter of judicial precedent. …