Influence of electricity on post-mortal body temperature

In a case of suicidal application of electricity differences between the rectal temperature of the body and the suspected time of death were observed. In order to answer the question whether an electric current from hand to hand over >30 min led to a rise in body temperature FEM-based computer simulations and animal experiments were carried out. Both resulted in a warming of the soft parts in the arm without warming the body core. Thus a temperature-based estimation of the time since death can also be used in cases with electricity as the cause of death. Besides, in the animal experiment we found a spontaneous rise in the body core temperature even without application of electricity which may be a reason for the typical temperature plateau after death.     

An experimental model of death from anaphylactic shock with compound 48/80 and postmortem changes in levels of histamine in blood

The present study was made on an experimental animal model of a death from anaphylaxis, in which postmortem changes in levels of histamine and 1-methylhistamine, in whole blood were measured. Instead of the usual immunological method administering compound 48/80, a degranulating agent of mast cell and the effect closely resembling the immuno-reaction, resulted in reliable death in a short time. The animals that died rapidly after the injection of compound 48/80, were found to have large increases in levels of histamine and 1-methylhistamine soon after the administration. These results were similar to the results of injecting histamine exogenously. On the other hand, the animals that died after a longer time showed no increases in levels of those amines within about 24 h, but 24 hours after death histamine levels were only increased tremendously without rise in 1-MHA levels. These phenomena closely resembled those in the control animals that were treated with overdoses of Nembutal.     

A Nonlinear Least Squares Approach to Time of Death Estimation Via Body Cooling

The problem of time of death (TOD) estimation by body cooling is revisited by proposing a nonlinear least squares approach that takes as input a series of temperature readings only. Using a reformulation of the Marshall–Hoare double exponential formula and a technique for reducing the dimension of the state space, an error function that depends on the two cooling rates is constructed, with the aim of minimizing this function. Standard nonlinear optimization methods that are used to minimize the bivariate error function require an initial guess for these unknown rates. Hence, a systematic procedure based on the given temperature data is also proposed to determine an initial estimate for the rates. Then, an explicit formula for the TOD is given. Results of numerical simulations using both theoretical and experimental data are presented, both yielding reasonable estimates. The proposed procedure does not require knowledge of the temperature at death nor the body mass. In fact, the method allows the estimation of the temperature at death once the cooling rates and the TOD have been calculated. The procedure requires at least three temperature readings, although more measured readings could improve the estimates. With the aid of computerized recording and thermocouple detectors, temperature readings spaced 10–15 min apart, for example, can be taken. The formulas can be straightforwardly programmed and installed on a hand‐held device for field use.     

Validation of a new method of providing case-specific time-of-death estimates using cadaver temperatures

The near ubiquitous presence of numerical simulation has made case-specific calculations of body temperatures following death possible so that accurate calculations of body temperatures can provide valuable information for estimating the time of death and can aid in forensic investigations. Here, a computational approach is described that has been validated against multiple, independent, and experimental investigations. The approach only requires one subjective input parameter (the heat transfer coefficient). A simple algorithm serves as a guidepost to the selection of this parameter. The algorithm incorporates clothing and the space in which the body is housed. Heat transfer coefficients that range from h = 2 W/m²/°C for bodies that are heavily clothed to h = 9 W/m²/°C for bodies that are nude (in air). The method also requires setting of ambient temperature conditions (ambient temperature)—however, that input is often available. The paucity of inputs makes this technique remarkably easy to employ. The new method is also able to calculate cadaver cooling rates for situations where the cadaver is in a timewise or spatially changing thermal environment (diurnal temperature variations, bodies partially submerged in water, changes to weather, insolation, etc.). Results from the present calculations are compared with a large body of measurements from the literature; it was found that the predictions and measurements were in excellent agreement, regardless of the ambient temperature conditions and the nature of the clothing of the body. This new calculation approach can be used with reasonable accuracy for determining cadaver cooling and time since death.     

Study on electrocution death by low-voltage

Seven cases of electrocution death by low voltage (<80 V) were studied. Autopsy was carried out and the death scene was investigated. The conditions for low-voltage electrocution death, the state of the victim at the time of electrocution, postmortem examination and the nature of the electricity is discussed. It was pointed out that low-voltage electrocution was related to the nature of electricity, individual characteristics and environment conditions.     

A New Method for Determination of Postmortem Interval: Citrate Content of Bone*

Abstract: Few accurate methods exist currently to determine the time since death (postmortem interval, PMI) of skeletonized human remains found at crime scenes. Citrate is present as a constituent of living human and animal cortical bone at very uniform initial concentration (2.0 ± 0.1 wt %). In skeletal remains found in open landscape settings (whether buried or not), the concentration of citrate remains constant for a period of about 4 weeks, after which it decreases linearly as a function of log(time). The upper limit of the dating range is about 100 years. The precision of determination decreases slightly with age. The rate of decrease appears to be independent of temperature or rainfall but drops to zero for storage temperature <0°C.     

Thermal requirements of immature stages of Chrysomya albiceps (Diptera: Calliphoridae) as a common forensically important fly

Entomological material may be used to estimate the time since death occurred (postmortem interval, PMI) in forensically obscure cases. The method that is commonly used to calculate minimum post-mortem interval (mPMI, i.e., the least amount of time since one can be confident death occurred) is based on the relationship between insect development and ambient temerature. Isomegalen and isomorphen diagrams are among methods allowing to calculate the age of necorphagous insects, yet thermal summation models provide the most precise and acurate estimations. The digrams are prepared based on the length or the developmental stages of the larvae as a function of time and mean ambient temperature. A knowledge of thermal requirements, in particular lower temperature threshold (D_z) at which development of a species terminates, is of essential importance to calculate ADD (Accumulated Degree Days). In this study different temperature regimes were used to construct the isomorphen diagram, examinate changes in larval body length at different ambient temperatures and to estimate the thermal requirements for developemnt of Chrysomya albiceps, the most common dipteran species reported on human and animal cadavers in Iran. Six development events including hatching, 1st ecdysis, 2nd ecdysis, wandering, pupariation and eclosion were studied under eleven constant temperature regims (17–37 ⁰C). The development rate of Ch. albiceps increased as temperature increased. The larval length peaked at the end of third stage and then decreased at wandering stage. The maximum larval length occurred at 72 h post oviposition at either 31, 33, or 35 °C. At 17 °C, larvae did not hatch from eggs and at 37 °C wandering larvae did not proceed to pupariation, and thus larval development were analysed at the nine left over temperatures. The development stages required at least (D_z ± SE) 13.04 ± 0.37, 14.29 ± 0.45, 15.69 ± 0.56, 15.18 ± 0.56, 14.94 ± 0.48, and 11.23 ± 0.41 °C to reach one of the successive developmentl events, respectively. The estimated thermal summation constant (k) for those the six events were 10.43 ± 0.27, 19.31 ± 0.32, 27.87 ± 1.3, 55.94 ± 1.82, 66.69 ± 3.5, and 143.52 ± 5.61 ADD accordingly.     

Estimating the Time of Death in Domestic Canines

Abstract:  Because 36.1% of U.S. households have dogs, the time of death (TOD) of dogs at crime scenes can be useful to forensic investigators. However, there are few published studies based on postmortem changes in dogs. This study, conducted indoors in still air at approximately room temperature, monitored the postmortem reduction in rectal, liver, brain, and aural temperatures in 16 dogs for 32 h after death. Graphs of temperature reduction were prepared to estimate the TOD of dogs within the first 32 h postmortem. Sex, body mass, and hair coat density did not affect the rate of body temperature reduction, but increased body weight and volume slowed it. Rectal temperature was the most convenient, reasonable site for measuring body temperature. Vitreous humor potassium ion concentration [K⁺] was measured in both eyes at c.  1.5 and 7 h after death. Both eyes had the same [K⁺] when measured simultaneously, and [K⁺] increased after death.     

Estimation of the post mortem period by multiple-site temperature measurements and the use of a new algorithm

The estimation of the post mortem period, in cases where death occurred under suspicious circumstances, is usually attempted using temperature measurements taken at a single body site. Early investigations of the validity of such an approach use the abdominal skin surface, the axilla and the rectum as measurement sites (B.H. Knight, Forensic Sci. Int., 36 (1987) 47-55). However, it has recently become more common to use the rectum alone, though the ear and the nasal passages have also been utilized. Whatever site is employed, the estimates are frequently found to be inaccurate. There are several fundamental reasons for these inaccuracies, the most prominent being the unknown variation in the ambient temperature between the time of death and the commencement of measurements, and the unknown body temperature at the time of death. This paper proposes a method of overcoming the above difficulties by taking a series of measurements concurrently at a number of body sites, a technique used by several previous workers (B.H. Knight, Forensic Sci. Int., 36 (1987) 47-55). Initial investigations have shown that an improved estimation of post mortem period is obtainable by the application of a suitable decision-making algorithm.     

利用积温和昆虫发育历期推测死亡时间的研究

目的积累尸食性蝇类虫态发育历期和积温的资料。方法采用动物尸体作诱饵,分别对自然飞到诱饵上繁殖生长的6种尸食性蝇类的虫态发育历期和积温进行观察研究。结果经过观察,取得了棕尾别麻蝇、丝光绿蝇、紫绿蝇、宽丽蝇、巨尾阿丽蝇、大头金蝇等6种尸食性蝇类的虫态发育历期和积温的基础数据。并采用倒计积温的方法推测实际案例中死者死亡时间,破案后证实推测时间与实际死亡时间一致。结论本文数据可为利用尸食性蝇类虫态育历期的积温推测死亡时间提供依据。     

Hyperthermia,Thermal Injuries,and Death from a Forced Convection Heat Source: A Case Report and Experimental Model

Heat‐related deaths of children are most often encountered in the context of enclosed vehicles in summer months. Deviating from this, a 16‐month‐old boy was found unresponsive in a stroller that was placed adjacent to a space heater during mid‐winter. The cause of death was hyperthermia and thermal injuries. Manner of death determination was difficult due to alleged surrounding circumstances. To understand the time‐course of this child's injuries, a child death scene investigation was performed; the stroller and space heater were recovered. In a re‐enactment of the events, a slaughtered pig approximating the child's size was warmed using a water bath and placed in the stroller beside the space heater. Cutaneous temperature measurements showed rapid initial temperature rise with subsequent steady increases. Tanning of the skin was seen on periodic direct observations. Internal temperature monitoring illustrated steady increases. This experiment was essential in classifying the manner of death as homicide.     

Deaths associated with electric shock injuries in children and adults: A 10-year retrospective examination in Şanlıurfa,Southeast Turkey (2012–2022)

Electric shock injuries (EIs) have high rates of morbidity and mortality in both children and adults. The aim of this study was to examine autopsy cases resulting from EIs and to compare pediatric and adult groups with respect to sociodemographic data, clinical characteristics, location of the incident, electricity entry–exit wound characteristics, current direction, pathological effects of the electric shocks on the body, and cause of death. A total of 8075 autopsies conducted between 2012 and 2022 were retrospectively examined. Şanliurfa is a city in the southeast of Turkey with the highest birth rate in the country. Of 123 cases of death resulting from EIs in Şanliurfa, 58 (47.2%) were children (age < 18 years). In the majority of children (81%), a low-voltage injury resulted from a domestic appliance while the children were playing at home in a rural area. In the vast majority of adults, a high-voltage injury (HVI) resulted from a workplace accident due to working with HVI materials in an area outside the home. The manner of death was accidental in all the electric shock injuries. The electricity entry and exit wounds formed as a result of EIs had similar characteristics in both children and adults, with no significant difference identified. In the province of Şanliurfa, Turkey, which borders Syria and where the main occupation is agricultural activities, there is a need to increase electrical safety precautions within the home, educate parents, and increase electrical safety conditions and worker education in the workplace.     

Comment on the Marshall-Hoare-Henssge model for estimating the time since death

Timewise temperature variations in objects that are undergoing unsteady heating or cooling is a commonly encountered problem in the thermal sciences. One particular area of application is the cooling of a body post-death and the use of body temperatures to estimate the time of death. Here, a new approach based on the theory of transient heat transfer is formulated to allow efficient calculation of unsteady conduction problems. The theoretically derived unsteady temperature models are compared with experimentally based correlations (the Marshall-Hoare-Henssge model). The two approaches are found to agree very well. With this new theoretically based approach, timewise temperature variation can be calculated for both large and small Biot number transient problems.     

Comparative evaluation of postmortem serum concentrations of neopterin and C-reactive protein

The cellular immune response is accompanied by the release of neopterin. The level of neopterin in serum is increased in patients suffering from viral infections, autoimmune diseases, systemic inflammation, allograft rejection and malignant diseases, while that of C-reactive protein (CRP) is known to rise during inflammatory diseases and traumas. To investigate postmortem neopterin and CRP concentrations with regard to the cause of death, we examined cardiac and peripheral blood samples in 474 autopsy cases without advanced decomposition (0-96 years of age, 343 males and 131 females), 2.8 h to 3 days (median, 18.0 h) after death. Survival time was 0.1 h to 5 months (median, 3.0 h) for traumatic death, and 0.1-1, 440 h (median, 2.5 h) for natural death. In autopsied subjects, neopterin concentrations were higher than the clinical reference, independent of the time after death, and depended on the survival time. In cases of acute and subacute death due to trauma, the neopterin level in right heart blood was mildly to moderately elevated (about 50-200 nmol/l) except for sharp instrument injury, whereas the CRP concentration usually remained low (<1 mg/dl). However, a moderate rise in the CRP level (around 1-10 mg/dl) was observed in fatal cases of hypothermia (cold exposure). Markedly elevated serum CRP and neopterin levels (>10 mg/dl and >500 nmol/l, respectively) were detected in cases of delayed death due to trauma involving systemic inflammatory response syndrome (SIRS) and of fatal bacterial infections. For sepsis, the serum CRP level was markedly elevated but the neopterin level was low in some cases. Fatal viral infections usually resulted in a marked elevation in the serum neopterin level (>500 nmol/l) with a mild to moderate rise in the CRP level. Combined analyses of neopterin and CRP may be useful to investigate viral infections and delayed traumatic death involving SIRS to support pathological findings.     

An autopsy case of infant death due to heat stroke.

We report an autopsy case of infant death due to heat stroke. On a winter day, a 52-day-old female baby was placed under a Japanese electric foot warmer with a coverlet (kotatsu) on an electric carpet warmer in a heated room at home. After about 5 h, the mother noticed that the baby was unconscious and took her to a hospital. Spontaneous respiration, however, was already absent, and the pupils were dilated. The trunk was hot; body temperature was 41.3 degrees C. The skin of the whole body was dry. Autopsy revealed second-degree burn injuries on the left side of the face and the dorsum of the left hand. Numerous marked petechiae and ecchymoses were found in the thymus (capsule and parenchyma), pleurae (visceral and parietal), pericardial cavity (internal and external surfaces), epicardium, and beneath the serosa at the origin of the aorta. In addition, there was congestion in various organs, edema in the brain and lungs, and hemorrhage in the lungs. Histopathologically, macrophages without hemosiderin granules were present in the alveoli. When the heating conditions at the accident were reproduced experimentally, the temperature in the electric kotatsu warmer rose to 50-60 degrees C. Thus, we concluded that misuse of the electric kotatsu caused heat stroke in this infant.     

Problems in the evaluation of electrocution fatalities in the bathtub

Forty-eight cases of electrocution in the bathtub are reported which were recorded in Düsseldorf and G?ttingen from 1972 to 1986; 19 cases were established to be suicides, with a sex ratio of 1:3 in favor of females. Marks of electricity were found in 8 cases. Five other cases were distinguished by linear marks indicating the water level, and in 10 cases a peculiar restriction of the postmortem hypostasis on the submersed areas could be seen. We presume from our own material that the latter findings can be easily ignored. As linear, circumscribed lividity could not be detected in bath deaths without electricity, it may be a specific finding. We recommend that more attention be paid to this phenomen. In all of our cases, 220 V current was involved, i.e., the usual household supply. The calculated amperage was about 100 to 250 mA, which means that ventricular fibrillation occurred within a few seconds. In 14 cases foam was established at the mouth and the nostrils, or in the air passages. We presume that, in these cases, death by electrocution was finally superimposed by drowning without developing the typical emphysema aquosum.     

Predicting the postmortem interval using human intestinal microbiome data and random forest algorithm

Gradual changes in microbial communities in a human body after death can be used to determine postmortem interval (PMI). In this study, gut microflora samples were collected from the vermiform appendix and the transverse colon of human cadavers with PMIs between 5 and 192 h. The results revealed that the appendix might be an excellent intestinal sampling site and the appendix flora had an inferred succession rule during human body decomposition. Firmicutes, Bacteroidetes, and their respective subclasses showed a predictable succession rule in relative abundance over time. A Random Forest regression model was developed to correlate human gut microbiota with PMI. We believe that our findings have increased the knowledge of the composition and abundance of the gut microbiota in human corpses, and suggest that the use of the human appendix microbial succession may be a potential method for forensic estimation of the time of death.     

Time of death of victims found in cold water environment

Limited data is available on the application of post-mortem temperature methods to non-standard conditions, especially in problematic real life cases in which the body of the victim is found in cold water environment. Here we present our experience on two cases with known post-mortem times. A 14-year-old girl (rectal temperature 15.5 degrees C) was found assaulted and drowned after a rainy cold night (+5 degrees C) in wet clothing (four layers) at the bottom of a shallow ditch, lying in non-flowing water. The post-mortem time turned out to be 15-16 h. Four days later, at the same time in the morning, after a cold (+/- 0 degrees C) night, a young man (rectal temperature 10.8 degrees C) was found drowned in a shallow cold drain (+4 degrees C) wearing similar clothing (four layers) and being exposed to almost similar environmental and weather conditions, except of flow (7.7 l/s or 0.3 m/s) in the drain. The post-mortem time was deduced to be 10-12 h. We tested the applicability of five practical methods to estimate time of death. Henssge's temperature-time of death nomogram method with correction factors was the most versatile and gave also most accurate results, although there is limited data on choosing of correction factors. In the first case, the right correction factor was close to 1.0 (recommended 1.1-1.2), suggesting that wet clothing acted like dry clothing in slowing down body cooling. In the second case, the right correction factor was between 0.3 and 0.5, similar to the recommended 0.35 for naked bodies in flowing water.     

Postmortem decrease in brain temperature.

The postmortem decrease in central brain temperature in a small number of forensic cases is presented. Each case shows a simple exponential fall during the time of the measurements. The data reported by Brinkmann et al. (1978), when plotted in semilogarithmic coordinate system, also show--after an initial "plateau" of about 2 h--a strictly one-term exponential temperature fall for several hours post mortem. The curve of brain temperature fall allows conclusions about the time of death without considering clothing, body stature, and weight. The interval temperature measurements which are required may be obtained on the spot, and the calculations needed are very simple. The method, therefore, seems preferable to those depending on rectal temperature measurements.     

Post-mortem changes in skeletal muscle protease and creatine phosphokinase activity — A possible marker for determination of time of death

The pattern of change in activity of two enzymes in rat skeletal muscle during body storage after death has been determined. Myofibrillar protease activity was found to increase linearly with time of storage post mortem at room temperature but not at 4 °C. In contrast, creatine phosphokinase activity declines linearly with time, and again storage at 4 °C prevented the change in enzyme activity. Starvation of animals for 5 days or forced exercise prior to death did not markedly alter the rate of change in activity of the two enzymes, although creatine phosphokinase specific activity at time of death was higher in the starved and exercised rats as compared to control animals. A plot of the logarithm of protease/creatine phosphokinase specific activities ratio versus time post mortem yields a linear curve at room temperature. These observations offer a potential method for estimating time of death.