Does DNA evidence trump all other evidence? An examination of the effects of common homicide trial evidence and mock jurors' verdicts.

摘要

Every day jurors are asked to listen to numerous pieces of evidence at trial and decide the fate of another person. How exactly jurors reach their decisions, however, is still unclear. The present research sought to examine this by exploring how jurors weigh a variety of pieces of evidence and how those weights interact to lead to verdict decisions. This was done using an inductive approach across three main studies. Study 1 asked mock jurors how important 41 pieces of evidence (derived from Schweitzer, Krewson, Harrell, & Nunez, 2014) were to them when deciding a verdict and found 10 pieces of evidence that mock jurors rated as most important: DNA, fingerprints, weapon, video records, crime scene photos, gunshot residue, other bodily secretions, video confession, forensic expert testimony, and eyewitness testimony. Study 2 expanded on Study 1 using a different methodology; mock jurors were given four pieces of evidence and asked to choose the order with which they would like to view the evidence, allowing for a different measure of importance. Results indicated that mock jurors sought out DNA evidence first, then video confession, eyewitness testimony, and fingerprint evidence. Study 3 utilized and furthered the findings of the previous studies and examined how the presence and absence of highly important evidence affected mock jurors' verdicts. Results indicated that video confession and fingerprint evidence were equally as important to mock jurors no matter if present or absent at trial. Findings regarding DNA and eyewitness evidence were less clear. Implications are discussed.