Revisit of Forensic Analysis of Arsenic Poisoning Case 1998

High energy synchrotron radiation X-ray fluorescence (SR-XRF) spectra for the forensic analysis of Wakayama arsenic poisoning case, Japan, were revisited. The spectra were measured at SPring-8 synchrotron facility by Nakai in December 1998 and Mo, Sn, Sb, and Bi were used as index elements at that time to demonstrate that the suspected saleswoman’s pesticide and that found near the curry pot were the same. The pesticide was identical with respect to Mo, Sn, Sb, and Bi, because these impurity elements were originated from the smelting process of arsenic ore. Based on the analysis of Mo, Sn, Sb, and Bi XRF peaks, the suspect was sentenced to death without her confession. In the present paper, the importance of bench-top XRF spectrometer analysis (Si and Ca) as well as the importance of the ordinary X-ray diffraction are pointed out for identification, which were neglected in the court.