Journal of Forensic Research

The Importance of Forensic Evidence in Establishing Criminal Guilt

Abstract

Shichun Ling

According to recent research, the general public has the perception that forensic evidence is prone to error and requires considerable human judgment. By comparing decisions on guilt and punishment in criminal cases that involve forensic versus eyewitness testimony evidence and determining whether there is a CSI effect, this study examines how important the general public finds forensic evidence. In particular, the experimental survey used a 2 (crime type: murder or rape) 4 (type of evidence: DNA, fingerprint, eyewitness testimony from a victim or bystander, or eyewitness testimony from a bystander) 1 design, which produced seven vignettes to which participants were randomly assigned. According to the findings, forensic evidence was linked to a greater confidence in a guilty verdict and a higher number of guilty verdicts. The ideal sentence length and the expected sentence length were both unaffected by forensic evidence. However, when forensic evidence was presented for rape, respondents thought the defendant should receive a longer sentence, but the likely sentence respondents expected the defendant to receive did not change. This study did not find evidence of a CSI effect. In general, this study suggests that DNA and other forensic evidence have a greater impact during the verdict stage than during the sentencing stage.