Re-evaluating RAPD-based plant DNA evidence from the 1992 maricopa homicide investigation: a modern reassessment of the first court-accepted molecular botanical evidence

The 1992 Maricopa homicide investigation introduced the first court-accepted molecular botanical evidence, marking the beginning of the forensic application of plant DNA profiling. Despite its historical significance, the scientific weight of the RAPD-based evidence has never been comprehensively re-evaluated under contemporary forensic and legal standards. This study re-examines the Blue Palo Verde ( Parkinsonia florida ) seed pod evidence by reassessing its statistical weight using modern population genetics principles and evaluating its admissibility under the transition from the Frye to the Daubert standard. The paper contextualizes the case within the evolution of plant DNA profiling, from RAPD to modern SNP-based genomic approaches. The analysis indicates that while the RAPD evidence was groundbreaking for its time, its limited reproducibility, lack of established error rates, and constrained statistical foundation would substantially reduce its evidential weight under modern scientific expectations. These findings demonstrate how historical forensic evidence can be critically reinterpreted under modern scientific and legal standards.