256例命案尸体死亡时间推断的回顾性分析

目的探讨降低死亡时间推断误差的方法。方法收集常州市和南京市2003年1月一2013年1月256例已破命案．采用传统方法进行死亡时间推断，与破案后获得的实际死亡时间进行比较，并根据死亡时间进行分组，计算死亡时间推断准确率，分析判断错误原因。结果早期尸体死亡时间（≤12h和13～24h）推断准确率分别为90％、89％，晚期尸体死亡时间（1—7d、1～2周、3～4周、1～6个月、7～12个月和1～5年）的推断准确率随时间的延长下降，分别为79％、76％、83％、79％、60％和50％。推断方法不当、水中尸体、极端温度、客观依据不足、抛尸以及变动或破坏现场是影响死亡时间推断准确率的常见因素。结论综合参考多项指标可降低死亡时间推断的误差。

A Retrospective Analysis of Estimating Postmortem Interval in 256 Murder Cases

Objective To discuss the method of reducing error in estimating postmortem interval （PMI）. Methods Two hundred and fifty-six solved murder cases from 2003 January to 2013 January in Changzhou and Nanjing City were collected, The PMI of all cases was estimated by traditional method and then compared with the real PMI obtained after the cases were solved. The cases were grouped according to the PMI, the accuracy was calculated, and the reasons of suboptimal PMI were analyzed. Results The accuracies of early PMI （less than 12h and 13-24h） were 90% and 89%, respectively; while the accu- racies of late PMI （1-7d, 1-2 weeks, 3-4 weeks, 1-6 months, 7-12 months and 1-5 years） decreased over time, being 79%, 76%, 83%, 79%, 60% and 50%, respectively. The common reasons of estimating error included improper inference methods, water submerged body, extreme temperature, lack of objective evidence, intentionally abandoned body, and changed or destroyed scene, etc. Conclusion The multiple index data can reduce the error in estimating PMI.