Trends in forensic autopsy in Chiba prefecture over the past decade

The death investigation system in Japan is in the midst of a great transformation. As part of efforts to revise this system, in this study we analyzed the reasons the police refer unnatural death cases for forensic autopsy and, from an understanding of the trends of such referrals, we discuss the future direction of handling unnatural deaths in our country. For 1618 forensic autopsy cases handled by the First Investigation Division of Chiba Prefectural Police that were referred to our institution for forensic autopsy between 2003 and 2012, we tallied the number of autopsies by sex, age group, and reason for forensic autopsy for each year and investigated trends in the referrals over time. The results revealed that the number of autopsies increased annually from 2003 to 2012, with a marked increase from 2010. The number of autopsies increased particularly for cases of suspected criminal deaths, where it was unclear to the police before the forensic autopsy whether or not the death resulted from a criminal act. Our findings suggest that the number of forensic autopsies will continue to increase into the future in Chiba prefecture, and is a trend that is inevitable if we are to prevent criminal death cases from being overlooked. Although referrals for forensic autopsy in Japan are made only when criminal activity is suspected, the original purpose of death investigations is not only to avoid overlooking crimes, but also to flag public health issues. Therefore, together with the police, we need to review the original purpose and conduct more in-depth discussions about when referrals are necessary.