The Impact of Narrative Consistency on Jurors' Utilization of DNA Evidence

The Story Model of Juror Decision Making states that as jurors are exposed to new pieces of evidence, they continually integrate evidence into a “story” about what happened in the case; this process includes evaluating contradictory testimony and discounting evidence that does not fit within the juror’s narrative about the case. Existing research has neglected to test how forensic DNA evidence is incorporated into jurors’ narratives, especially if the DNA is inconsistent with the non-forensic evidence. The lack of emphasis on forensic evidence should be addressed given the perception of infallibility that surrounds DNA. Study 1 manipulated non-forensic evidence strength and whether there was a DNA match to test how jurors integrated DNA evidence into their narrative interpretation of the case. Results indicated that utilization of forensic testimony depended on the non-forensic evidence strength and reliance on non-forensic evidence depended on whether there was a DNA match. To expand the results from Study 1 and incorporate the possibility of error in DNA testing, Study 2 manipulated whether a DNA match did or did not contain laboratory error rate evidence and the strength of the non-forensic evidence to examine how jurors integrate error rates into their narrative about a case. Results showed that jurors were not sensitive to the laboratory error rates manipulation. Together, these studies indicate that jurors are not sensitive to the possibility of erroneous DNA results, but integrate DNA identifications into their narrative; this suggests that bias might be integrated into their narratives that facilitate false convictions