Assessment of post-mortem submersion interval using total aquatic decomposition scores of drowned human cadavers

Investigating drowning-related deaths remains a significant problem for forensic personnel all over the world. The previously published decomposition scoring method like the total aquatic decomposition (TAD) score promises to estimate the correct post-mortem submersion interval (PMSI) in aquatic habitats through the assessment and calculation of the decomposition rate and accumulated degree days (ADD). The current study comprised of 53 drowned death cases belonging to various districts of Haryana from May 2016 to August 2017. The regression and Pearson's correlation indicated a significant correlation between the TAD scores and the actual ADD (calculated through water temperatures) (r² = 0.917) and between the actual and the estimated ADDs (calculated through TAD scores used by Heaton et al. [21]) (r = 0.9585). The results indicated that the estimated ADD tends to over predict the PMSI compared to the actual ADD. It is further confirmed by paired t-test, which showed the mean of actual ADD (mean = 349) to be significantly lower than the mean of estimated ADD (mean = 663). Moreover, these methods will help forensic investigators and researchers formulate region-specific regression equations for PMSI estimation.     

Determination of Time since Death using Vitreous Humor Tryptophan

Determination of time since death (TSD) plays very important role in forensic examination as it narrows down field of suspects and aids in deceased identification. This study utilizes the fluorescence property of vitreous humor (VH) tryptophan to determine TSD using o‐phthalaldehyde (OPA). The detection limit of these fluorometric studies was found to be 8 ppb indicating sensitivity and high accuracy in TSD determination. The study was performed on selected 76 cadaver with known TSD ranging from 3 to 90 h. Excellent correlation between VH tryptophan and TSD was obtained with a coefficient of correlation R² = 0.9590. Results showed statistically significant increase in vitreous tryptophan with TSD up to 90 h, and the proposed method was efficaciously applied for prediction of TSD as no systematic error exist. The regression equation obtained from the study is [Trp] = 2.21 + 2.98 * TSD.     

呼和浩特夏秋季嗜尸性苍蝇群落组成与演替

目的研究呼和浩特夏秋季常见嗜尸性苍蝇生态群落组成与演替规律。方法连续3年用观察法研究7—10月份,家兔、狗尸体、鸡、鱼内脏等试验材料上的嗜尸性苍蝇生态群落组成与演替。结果该地区上述尸体上出现的双翅目嗜尸性苍蝇是最先到达尸体上的昆虫,而且在尸体上出现时间及部位表现出很强的生态群落演替规律性。结论研究结果可成为在呼和浩特地区对尸体进行死亡时间、死亡地点推断的依据。     

Time burnt away: The impact of heat-induced changes on skeletal age-at-death diagnostic features

This paper investigates the established notion that bone calcination has a major impact on age estimation while low-intensity burns have a mere negligible impact. Few systematic researches have been carried out so far about this topic so the true impact of heat-induced changes on diagnostic age features is mostly unknown.The agreement between pre-burning and post-burning observations of age features was investigated on 51 human skeletons (22 males and 29 females with ages-at-death ranging from 61 to 93 years old) subjected to experimental burns. These skeletons belong to the 21st Century Identified Skeletal Collection housed at the Laboratory of Forensic Anthropology of the Department of Life Sciences, University of Coimbra, Portugal. The Suchey-Brooks method based on the pubic symphysis and the method developed on the auricular surface by Buckberry and Chamberlain (2002) were scrutinized.The Suchey-Brooks method provided better agreement between pre- and post-burn observations than the method from Buckberry and Chamberlain (2002). However, it became clear that heat-induced changes affected both methods regardless of heat intensity since both calcined bones and bones burnt at lower intensities often showed less than perfect agreement. Therefore, this research demonstrates that the analysis of age-at-death can be impaired in burnt bones, even those not subjected to calcination, with clear impact for forensic and archaeological investigations.     

Time since death determinations of human cadavers using soil solution.

This study was conducted to collect data on specific volatile fatty acids (produced from soft tissue decomposition) and various anions and cations (liberated from soft tissue and bone), deposited in soil solution underneath decomposing human cadavers as an aid in determining the "time since death." Seven nude subjects (two black males, a white female and four white males) were placed within a decay research facility at various times of the year and allowed to decompose naturally. Data were amassed every three days in the spring and summer, and weekly in the fall and winter. Analyses of the data reveal distinct patterns in the soil solution for volatile fatty acids during soft tissue decomposition and for specific anions and cations once skeletonized, when based on accumulated degree days. Decompositional rates were also obtained, providing valuable information for estimating the "maximum time since death." Melanin concentrations observed in soil solution during this study also yields information directed at discerning racial affinities. Application of these data can significantly enhance "time since death" determinations currently in use.     

Detection of diverse aquatic microbes in blood and organs of drowning victims: first metagenomic approach using high-throughput 454-pyrosequencing

Current 454-pyrosequencing technology enables massive parallel sequencing. We used this technology to investigate the diversity of aquatic microbes in 14 specimens (blood and organs) of two drowning victims and in two water samples taken from the discovery sites. The 16S ribosomal RNA (rRNA) genes of microbes, which are often used to identify species (or genera), have nine highly variable regions (V1-V9), each of which is surrounded by conserved regions. Some parts within the conserved regions are common over domains of microbes, such as between bacteria and algae (16S rRNA genes on algal chloroplast genomes). We therefore simultaneously amplified the target regions (V7 and V8) of various microbes in the blood and organs of drowning victims using PCR with custom-designed primers that were based on the conserved regions. We then exhaustively analyzed the PCR products by pyrosequencing using the Genome Sequencer FLX Titanium system (Roche-454 Life Sciences). This approach identified a wide array of bacteria including cyanobacteria and algae including Bacillariophyceae (diatom), Cryptophyceae, Dictyochophyceae, Chrysophyceae and Trebouxiophyceae in the blood and organs of the victims and water at discovery sites. Our data further indicated that when conventional diatom testing of lungs yielded insufficient evidence of water aspiration, the detection of various exogenous microbes by 454-pyrosequencing is very useful to support a conclusion of death by drowning. To the best of our knowledge, this is the first attempt to use a new generation sequencer to investigate diverse aquatic microbes in the blood and closed organs of drowning victims.     

Decomposition and insect succession of clothed and unclothed carcasses in Western Australia

The effect of clothing on carcass decomposition and patterns of insect succession onto remains were investigated in two separate years during autumn in Western Australia. The progression of decomposition differed between clothed and unclothed carcasses in both years of the study. The presence of clothing markedly prolonged the wet decay stage in both years with larval feeding occurring across the moist skin surface underneath clothing, as well as within and under the carcasses. Ambient temperatures were higher in the second year of the study and corresponded to marginally faster rates of decay throughout decomposition. Within years, insect arrival and oviposition were largely consistent between clothed and unclothed carcasses with a few notable exceptions. The green blow fly, Lucilia sericata Meigen (Diptera: Calliphoridae) oviposited one day earlier on clothed than unclothed carcasses in both years of the study. The black carrion fly, Australophyra rostrata Robineau-Desvoidy, (Diptera: Muscidae) colonised clothed carcasses in two distinct waves of succession but only one wave of ovipoistion was observed on unclothed carcasses in either year. Correspondingly, clothed carcasses supported larval feeding by A. rostrata for a longer duration than unclothed carcasses. Finally, dipteran larval masses were more widely distributed across the carcass surface and were present for a longer period of time on clothed carcasses than on unclothed carcasses in both years. Forensically relevant data detailing the seasonal pattern of insect succession onto clothed and unclothed decomposing remains in Western Australia are reported.     

Effect of carcass size on rate of decomposition and arthropod succession patterns.

Decomposition studies were conducted using two carcasses of domestic pigs, Sus scrofa L., 8.4 kg and 15.1 kg in weight, to determine the effects of carcass size on the rate of decomposition, composition of the arthropod fauna, and succession patterns. A total of 46 arthropod taxa were recovered during this study. No size-related differences were observed between carcasses with respect to composition of the arthropod fauna or patterns of succession. A greater number of arthropods were observed attracted to the 15.1-kg carcass, and the rate of decomposition observed was more rapid for the 15.1-kg carcass than for the 8.4-kg carcass. Internal temperatures of the 8.4-kg carcass were more directly related to external ambient temperatures during the fresh and bloated stages of decomposition. During the decay stage, both carcasses generated internal temperatures significantly above ambient temperatures. Following this stage, internal temperatures fell to approximate ambient temperatures during the postdecay and remains stages.     

A preliminary investigation of insect colonisation and succession on remains in New Zealand

A preliminary, systematic field study on the process of decomposition and associated insects was conducted, for the first time, in New Zealand. Using pig carcasses as an animal model for human decomposition, insect colonisation and succession was monitored in three different habitats in the Auckland region where remains are likely to be found. A significant difference in the rates of decomposition was found among the three different habitats of an open field, coastal sand dune area and native bush during the autumn/winter season. The primary colonisers of all carcasses were Calliphora stygia Fabricius (Calliphoridae), Chrysomya rufifacies Macquart (Calliphoridae) and Hydrotaea rostrata Robineau-Desvoidy (Muscidae). Two species were identified as possible representatives of the habitats in which they were found; Fannia sp. (Fanniidae) in the open field habitat and Calliphora hilli Patton (Calliphoridae) in the native bush habitat. Also identified was Sylvicola sp. (Anisopodidae) as a possible indicator of damp habitats as well as a likely indicator of a longer postmortem interval. This preliminary investigation presents a broad outline of the insects associated with remains and the order in which they appear in the Auckland region.     

青岛地区常见嗜尸性蝇种及其季节性分布研究

目的观察青岛地区嗜尸性蝇种季节性演替规律,为死亡时间推断提供参考。方法在室外设立田间观察场所,2012年4月1日开始至2013年4月1日,每月第1天6时放置猪尸,20min后开始观察,至18时,期间每小时观察1次;第3天以后,分别于7时、12时、18时各观察1次。观察时记录尸体上出现的昆虫种类、虫态、数量并采集相应标本,进行分类鉴定。结果可以观察到有嗜尸性蝇类侵袭尸体的月份为4月至11月,共发现3科23种蝇类,其中丝光绿蝇、大头金蝇和亮绿蝇数量位列前三,分别占全部观察数量的40.71%、31.95%和7.12%。丝光绿蝇、大头金蝇中午时段出现的数量显著多于早上和傍晚。一年中各种蝇类在中午出现的数量均多于早上及晚上。4月上旬,蝇类早、晚与中午出现的数量相差显著;而在7、8月份差别较小。大部分嗜尸性蝇种集中在新鲜期和肿胀期。结论本文观察数据可为利用嗜尸性蝇类演替规律进行法医学死亡时间推断,以及建立地区嗜尸性蝇种类数据提供参考。     

An initial study of insect succession and carrion decomposition in various forest habitats of Central Europe

At the end of summer and beginning of fall 2005 insect succession and pig carrion decomposition were studied in pine-oak forest, hornbeam-oak forest, and alder forest in Western Poland (Central Europe). Five stages of decomposition were recognized: fresh stage, bloated stage, active decay stage, advanced decay stage, and remains stage. The highest rate of decomposition was observed in the alder forest and the lowest in the pine-oak forest. A similar composition of carrion entomofauna was found in each forest. Numerous adults of Lucilia caesar, Phormia regina and Calliphora vomitoria (Calliphoridae), Hydrotaea spp. (Muscidae), Stearibia nigriceps and Parapiophila vulgaris (Piophilidae), Necrodes littoralis and Thanatophilus rugosus (Silphidae), Creophilus maxillosus, Omalium rivulare, Oxypoda acuminata and Philonthus spp. (Staphylinidae) as well as larvae of L. caesar, P. regina, C. vomitoria, Fannidae (Diptera) and N. littoralis, C. maxillosus, Philonthus (Coleoptera) were collected. There were no differences between forests in the sequence of insect occurrence on carrion. However, differences between forests in occurrence time and activity period of some taxa were found. Implications of these results for forensic entomology are discussed.     

侦查的时空维度

时间和空间不仅是侦查程序运行的平台,而且是侦查程序自身的构成要素。侦查领域的时空已经成为包含其自身在内的范畴体系。侦查价值理念可以在阐述与时空相关的范畴中得到重申,而立法技术也将侦查价值理念融汇到与时空相关的侦查概念、规则和原则中。     

Melody and Law's Mindfulness of Time

Abstract. A structured awareness of time lies at the core of the law's distinctive normativity. Melody is offered as a rough model of this mindfulness of time, since some important features of this awareness are also present in a hearer's grasp of melody. The model of melody is used, first, to identify some temporal dimensions of intentional action and then to highlight law's mindfulness of time. Its role in the structure of legal thinking, and especially in precedent‐sensitive legal reasoning, is explored. This article argues further that melody‐modeled mindfulness of time is evident also at a deeper and more pervasive level, giving structure to the distinctive mode of law's normative guidance. The article draws one important theoretical consequence from this exploration, namely, that the normative coherence of momentary legal systems depends conceptually on their coherence over time.     

Seasonality of insect succession and pig carcass decomposition in a natural forest area in southeastern Brazil

In this study, successional patterns, relative abundance of larvae and adults of sarcosaprophagous insects, carcass decay, diversity and seasonality of species, and their potential as forensic indicators were studied. Four experiments were carried out in each season in a natural area of southeastern Brazil. Two pigs (Sus scrofa L.) were used in each experiment and were exposed to sunlight and shade, respectively. The Calliphoridae outnumbered the Sarcophagidae in specimens collected and reared from the carcasses. More insects were collected from carcasses exposed to the sun, while a larger number of specimens were reared from those in the shade. Temperature and rainfall influenced the stages of carcass decay and insect activity and abundance. Chrysomya albiceps was the most abundant species in all four experiments. The carcasses were used as a protein source and substratum for oviposition. The dark putrefaction and fermentation stages yielded more flies than the other stages. These results show that flies are important in carcass decay and are, therefore, also of forensic importance. Seven species can be considered valuable forensic indicators in Southeastern Brazil. However, only three species were useful as forensic indicators in wooded areas: P. intermutans, H. segmentaria, and H. semidiaphana.     

The succession and development of insects on pig carcasses and their significances in estimating PMI in south China

The succession of insect communities on carrion varies at local and global spatial scales. As such, ecological succession data obtained from corpses at one geographic location cannot necessarily be applied to other locations. Our study describes this succession in the far southern part of China to provide such data for forensic cases in this region. A total of 18 pig carcasses were placed in the field in four seasons, and the timing of the following events were recorded: appearance of larvae, onset of larval wandering, when most larvae had wandered, onset of pupariation, when most larvae had pupariated, onset of eclosion and end of eclosion. Our results indicated that all of the evaluated events could be used as accurate indicators of postmortem interval (PMI). The carcasses decayed fairly quickly in spring, summer and autumn, taking 225+/-75 h, 183+/-44 h, and 247+/-70 h, respectively, to decay from the fresh stage to skeletonisation. In winter, carcasses needed longer (1180+/-291) to decay as much. Carcasses attracted 47 species of insect, with flies predominating. The larvae were mainly Chrysomya megacephala (Fabricius), Chrysomya rufifacies (Macquart) and Hydrotaea (Ophyra) spinigera (Stein). Most necrophagous insects were found all year around, and there were no marked differences in species among the four seasons, except that Dermestes maculatus (De Geer) was absent in winter. Blowflies produced only one generation on a carcass before it became skeletonised, which simplified the estimation of PMIs.     

Initial study of arthropods succession and pig carrion decomposition in two freshwater ecosystems in the Colombian Andes

Entomological succession and trophic roles of arthropods associated with different stages of carcass decomposition were studied to estimate the post-mortem submersion interval in two freshwater ecosystems in the Colombian Andes, at an altitude of 2614 m. Pig carcasses were employed as models placed 68 m apart, one in a stream (lotic) and another in an artificial lake (lentic). Decomposition time to skeletal remains was 74 days in the lake and 80 days in the stream. Six phases of decomposition were established: submerged fresh, early floating, floating decay, bloated deterioration, floating remains and sunken remains. A total of 18,832 organisms associated with the carcasses were collected: 11,487 in the lake (four orders, 19 families and 33 species) and 7345 in the stream (eight orders, 15 families and 25 species). Organisms were classified in the following ecological categories: shredders, collectors, predators, necrophagous, sarcosaprophagous and opportunists. Physical and chemical properties of the habitats, such as water temperature, CO(2) and conductivity, varied according to rainfall. In the lake, shredders (Coleoptera: Tropisternus sp. and Berosus sp.) and collectors (Diptera: Chironomus sp.) were found to be associated with submerged phases. Predators (Odonata) were only present during the first phases. Coleoptera (Dytiscidae) were found during floating decay and bloated deterioration stages. In the stream, shredders (Hyalella sp.) and collectors (Simulium sp.) were found during all stages, whereas the predator Oxelytrum discicolle was found exclusively during the floating stages, during which body temperature increased in a fashion similar to active decay in terrestrial environments.     

损伤鉴定所需时间与办案期限的冲突亟待立法解决

人体损伤程度的法医学鉴定所需时间,是指被鉴定人从受伤之日起到鉴定人发出鉴定文书之日止的时间,目前我国对此尚无明确的法定时限,因此,司法实践中经常出现损伤鉴定所需时间与办案期限发生冲突的现象,办案人员往往采取改变强制措施或退查案件等被动办法来弥补损伤鉴定所需时间,给办案工作带来极大不便甚至引起当事人或群众误解。笔者对产生这一现象的原因作了粗浅分析,并建议通过立法来解决这一矛盾。