Evaluation of the placenta in a stillborn fetus to estimate the time of death

The authors present a case of a presumably unknown pregnancy, in which the newborn was found dead in the bathroom. The child was considered stillborn and the death due to natural causes. The literature on estimation of the time of fetal death is reviewed. It has been reported that certain placental histological changes are useful in predicting the time of death in stillborn fetuses, but little has been published about their potential role. Furthermore, parameters evaluated by literature in examining the placenta for determining time of fetal demise in cases of stillbirth are not uniform in the few studies that have been published. We emphasize that any attempt to estimate the time of fetal death without an adequate knowledge of placental morphological changes is futile and forensically unjustifiable, and that a comprehensive placental, external, and histological examination of the fetus is still the method of choice to gain a reliable forensic answer.     

Identification and determination of age of needle tracks in human skin (author's transl)]

Examination of enzymic activities and histochemical reactions on needle pricks can be used to determine the age of micro-injuries with sufficient exactness. Well preserved skin shows patterns of enzymes which also appear with other skin injuries and which were described in detail especially by Raekallio (1970, 1972). In autolytical changes of the skin the adenosinetriphosphatase-reaction is still reliable and can be successfully estimated. If one has sufficient experience it is possible to fairly exactly estimate the age of an injury within the first hour after the injury by preparation of the adenosinetriphosphatase-reaction. If the times of injections are known one frequently succeeds in determining the time of death by exactly determining the age of the injury. In legal expertises the histochemical reactions can rightly be regarded as useful indications of a certain age of the injury. But they do not allow an exact estimate "beyond a reasonable doubt".     

The trials of Steven Truscott.

Determination of time of death (postmortem interval) is one of the most difficult problems confronting forensic pathologists. One noteworthy such case is that of Steven Truscott, a 14-year-old Canadian youth who was convicted of the June 1959 rape-murder of 12-year-old Lynne Harper in rural southwestern Ontario. The two had been seen together on the evening when Lynne was last seen alive. At her autopsy approximately 48 h later, the prosecutor, relying almost entirely on examination of the gastric contents, placed the time of death during the period in which the two were apparently in each other's company. Truscott's defense was unable to refute this opinion, and Truscott was sentenced first to death, then to life imprisonment. Isabel LeBourdais, a Canadian journalist, published a book defending Truscott that eventually led to a judicial rehearing, but his conviction was upheld. The examination of gastric contents is only one measure employed in the often difficult determination of time of death. It has not been made inherently more reliable in this regard since 1959. It is crucial, therefore, to use all available evidence in determining time of death.     

Comparison of chemical methods for determining postmortem interval

Accurate determination of postmortem interval (PMI) is a problem for the forensic thanatologist, especially in unwitnessed deaths. A number of objective chemical methods for determining PMI have been developed, the most widely used being accumulation of potassium in the vitreous humor. The authors previously have reported a chemical method for determining PMI from the predictable accumulation or clearance of the dopaminergic metabolite 3-methoxytyramine (3-MT) in the putamen of the brain. They have extended their previous study to compare directly the accuracy of determining PMI from the level of 3-MT in putamen with the level of potassium in vitreous humor. The data indicate that 3-MT is at least as accurate as, if not more accurate than, potassium accumulation in vitreous humor, although 3-MT levels can be affected by the cause of death and drugs present at the time of death. Nevertheless, determination of both the 3-MT and potassium levels can afford the most accurate method of determining PMI; preliminary nomograms for determining PMI from both variables are presented.     

A BASIC algorithm for calculating the postmortem interval from arthropod successional data.

A computer algorithm, implemented in the BASIC language, is presented for calculating the postmortem interval (PMI) from arthropod successional data. Entomology-assisted determination of the PMI promises to be a reliable technique in cases of homicide, suicide, accidental death, and unattended death due to natural causes. The program requires, as input, the identity of arthropod taxa recovered from human remains in a death scene investigation and machine-readable data on carrion-associated arthropod taxa and their known successional patterns of activity for the same geographical area. The program performs rapid comparisons of these lists and, on output, calculates an upper and lower estimate of the PMI, identifies the definitive taxa for these limits, and determines if the remaining corpse taxa have known successional patterns that are consistent for this estimate. An alternate output is provided if one or more corpse taxa do not overlap all the others at any single time in the succession. In that event, the user is prompted to recheck the identity of the non-overlapping taxon or taxa or reevaluate the environmental circumstances surrounding the case in question. Results of the analysis are saved to an ASCII file for output to a printer for making paper copies useful for the entomologist's Case Study Final Report. This program may make possible wider use of this technique in law enforcement and medical investigator offices that utilize both forensic entomologist expertise and IBM PCs (or compatible computers).     

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.     

The forensic entomologist in the context of the forensic pathologist's role.

An adequate death investigation requires the combined efforts and cooperation of experts in different disciplines: crime scene technicians, death investigators, forensic pathologists, anthropologists, entomologists, other medical and non-medical professionals. These front-line experts play a crucial role in every death investigation process. The forensic pathologist normally has the legal authority to take charge of the dead body at a death scene and his primary functions are the exterior and interior examination of the cadaver by analyzing the extent of antemortem injuries and the postmortem changes and the recovery of physical evidence. He is responsible for determining how, when and why of any death which is the result of violence, suspicious or unexplained circumstances or a death which is sudden or unattended, defending and explaining the reasons for making these diagnoses in a courtroom. The forensic entomologist can provide invaluable aid in death cases where human remains are colonized by insects and in the overall investigation. His principal role is to identify the arthropods associated with such cases and to analyze entomological data for interpreting insect evidence. He is responsible for determining the period of insect activity according to all the variables affecting insect invasion of remains and their development. The major goal of medico-criminal entomology is to contribute to the determination of the time, cause, manner and place of the investigated death (especially on badly decomposed corpses or skeletonized human remains) with the support of all the elements which can be inferred from the study of insects found on the cadaver or nearby. The application of techniques devised recently in forensic entomology can allow experts in the field to collect strong entomological evidence and provide useful information not only in a death investigation including movement or storage of the remains following death, time of dismemberment, postmortem artifacts on the body but also at the scene, and even more in child neglect, sexual molestation and identification of suspects. As the role of the forensic entomologist at the death scene, at the autopsy and in the laboratory is defined and well known, this paper focuses on the difficulties that could arise if forensic pathologists and entomologists are uncertain about the procedures that they have to follow, do not realize the value of objective findings or fail to evaluate them. Although every forensic case presents a slightly different set of circumstances and has to be tackled individually, the forensic pathologist should work with the forensic entomologist from the visual observations of the cadaver on the scene, through the collection of arthropods and temperature data at the death scene and at the autopsy, up to the final report with the interpretation of entomological and other biological evidence.     

Dating human skeletal remains using a radiometric method: biogenic versus diagenetic 90Sr and 210Pb in vertebrae

In forensic science, there is a strong interest in determining the post-mortem interval (PMI) of human skeletal remains up to 50 years after death. Currently, there are no reliable methods to resolve PMI, the determination of which relies almost exclusively on the experience of the investigating expert. Here we measured (90)Sr and (210)Pb ((210)Po) incorporated into bones through a biogenic process as indicators of the time elapsed since death. We hypothesised that the activity of radionuclides incorporated into trabecular bone will more accurately match the activity in the environment and the food chain at the time of death than the activity in cortical bone because of a higher remodelling rate. We found that determining (90)Sr can yield reliable PMI estimates as long as a calibration curve exists for (90)Sr covering the studied area and the last 50 years. We also found that adding the activity of (210)Po, a proxy for naturally occurring (210)Pb incorporated through ingestion, to the (90)Sr dating increases the reliability of the PMI value. Our results also show that trabecular bone is subject to both (90)Sr and (210)Po diagenesis. Accordingly, we used a solubility profile method to determine the biogenic radionuclide only, and we are proposing a new method of bone decontamination to be used prior to (90)Sr and (210)Pb dating.     

Automatic screening in postmortem toxicology

The systematic analysis of postmortem samples is one of the most challenging tasks in forensic toxicology. For determining cause of death, analysis of different tissues can be indispensable. Automation of these analyses would increase reproducibility and therefore lead to more reliable and comparable results. Recent developments in analytical toxicology and the availability of automation devices for various analytical stages, such as sampling, preliminary testing, sample extraction, chromatographic separation, identification, and data processing are examined and discussed. At present only parts of the analytical procedure have been automated-however, the goal should be the integration of these parts into a single, continuous process. Currently, only one "fully-automated" procedure for the comprehensive screening of blood and urine (excluding sample pretreatment, which remains separate) has been published. But it can be expected that automation of analytical procedures in forensic toxicology will indeed progress, even with regard to the very complex screening of postmortem samples.     

Thymic hyperplasia. A clue to the diagnosis of hyperthyroidism

The association of simultaneous abnormalities of the thyroid and thymus is well documented, particularly in the case of Graves' disease. We present a case of a natural death following thyroid storm in which marked thymic hyperplasia was present. This finding can be helpful in determining the cause of death.     

Wildlife forensic entomology: determining time of death in two illegally killed black bear cubs.

Forensic entomology is now commonly used to determine time of death in human death investigations. However, it can be equally applicable to wildlife crimes. This paper describes the use of entomology to determine time of death in the illegal killing of two young bear cubs in Manitoba, Canada. Two cubs were found shot, disemboweled, with their gall bladders removed. Natural Resource officers (Conservation Officers) and a Royal Canadian Mounted Police (R.C.M.P.) officer examined the remains, and the R.C.M.P. officer collected insect evidence. The only insects on the remains were adult blow flies coming to lay eggs and the blow fly eggs themselves (Diptera: Calliphoridae). The time of hatch was recorded and the insects were reared to adulthood. Time of hatch, together with species identification, macro and micro climate and lab developmental data were used to determine the time of death. The time was consistent with the time that the defendants were seen at the scene and was used in their conviction. This case illustrates that insect evidence can be equally as valuable in poaching cases as in homicide cases. However, in most cases Conservation Officers are unaware of this science. It is therefore, extremely important for more Conservation Officers to be educated about this field.     

Postmortem diagnosis of cerebral malaria

Human cerebral malaria is a frequent encephalopathy that occurs in the endemic tropical-subtropical zones. There are a smaller number of imported cases in continental zones where the diagnosis sometimes remains difficult to establish. Fifteen days after the death of a 36-year-old male French citizen in Africa, an investigation to determine the cause of death was conducted. Histologic examination of the brain permitted the diagnosis of cerebral malaria. Because of the popularity of overseas tourism and because this disorder may appear as "sudden death," these victims may be referred to a forensic pathologist. This case demonstrates the role a forensic pathologist may play in determining the cause of death in cerebral malaria.     

Entomological and Cardiologic Evidence of Time Since Death in Short Postmortem Intervals

Estimating the time since death of the deceased is a main goal in forensic investigations, but this can be challenging due to contradictory results derived from different investigations at the scene of death. We present a case of a 78‐year‐old woman, found dead in a small forest with broad‐leaved trees, whose husband had a history of domestic violence. Routinely performed investigations, such as postmortem rectal temperature and lividity, yielded inconsistent time since death results between only a few and longer than 20 h. This difficulty was most likely caused by high ambient temperatures of up to 38.0°C, which negatively influenced the informative value of the applied nomogram method. Additionally, performed entomological investigation of fly maggots (Lucilia illustris) recovered from the corpse and the assessment of heart pacemaker data revealed consistent and incontrovertible results. The presented case highlights the benefits of information provided by entomological investigations and data evaluation of cardiac implantable electronic devices and the combined use of the two techniques.     

Investigations into the analysis of the rate of decay of the compound action potentials recorded from the rat sciatic nerve after death: significance for the prediction of the post-mortem period

There have been a number of papers that have reported the investigations of electrical stimulation of muscle groups in order to determine the post-mortem period. To the authors knowledge, no techniques have been described that analyse the compound action potentials (CAP) of various nerve fibre groups after death. This paper reports the monitoring of both the amplitude and latency changes of the CAP recorded from a stimulated rat sciatic nerve after death. Initial results suggest that the method my be useful in determining the early post-mortem period within 1 or 2 h after death. It may also be of use in measuring nerve conduction delay in various pathological conditions that can affect the neural network; for example diabetes.     

A methodology based on NMR spectroscopy for the forensic analysis of condoms.

Both solution and solid state Nuclear Magnetic Resonance (NMR) spectroscopic techniques have been used to determine differences in commercially available condoms. Whilst solid state NMR is useful for determining the polymer backbone, it is not useful for forensic analysis due to the commonality of the latex condom. However solution NMR spectra obtained following a simple extraction procedure using hexane, provides a fingerprint of the additives in the lubricants. Following the development of a flow chart, basing decisions on the presence of particular peaks present in the solution spectra, 33 of 38 condoms could be individualized. Samples were also analyzed after having the lubricant manually removed and soaking the condom in water for 3 to 24 h. These experiments were performed to simulate a case of the sample having been used and disposed of by flushing down the toilet, as may be experienced in a case of a sexual assault. The results indicated that the only significant water soluble component was polyethylene glycol. The overall results suggest that the method developed may be a quick and useful technique in characterizing condoms. The information obtained can be used to provide associative evidence between suspect and crime, and so be useful in sexual assault cases.     

Determination of the time of death--integration of various partial methods

The criteria for estimating time of death, lividity and rigor mortis according to data worked out by Mallach, together with data concerning the mechanical excitability of skeletal muscles (Prokop), the electrical excitability of face muscles and pharmacologic excitability of the iris (Klein and Klein) were combined with a nomogram of the rectal/brain temperature at time of death to make a rational and practical method of estimating time of death that would be suitable for use at a scene of crime. In each actual case, only a few additional criteria can be used to verify the upper and lower limits of the nomogram readings and to reduce these defined limits. For this reason the outer data from Mallach's tables and Klein's results were separated into upper and lower limits, chronologically arranged and clearly presented. After rectal temperature measurement and corresponding nomogram reading, it is easy to recognize which further criteria must be examined. Analysis of the test results is extremely simple with the aid of the proposed chart.     

Electrical excitability of skeletal muscle postmortem in casework

The paper gives a review of the development of methods of postmortem electrical excitability of skeletal muscle for determining the time since death. For practical application in casework, the following method can be proposed: position of electrodes in the orbicularis oculi muscle, stimulation by rectangular impulses of 10 ms duration, 30 mA in a repetition rate of 50/s. The muscular reaction on excitation is graded in 6 degrees according to the spread of movement and the intensity of contraction. To each degree a time information is corresponding (95%-limits of confidence). These 95%-limits of confidence were proved to be valid for cases of sudden natural or traumatic deaths. Exclusions: deaths after chronic lingering disease (shorter times), fatal hypothermia, haematomas, emphysemas of the eyelid (longer times). The practical application in casework together with the temperature method (Henssge 1988, 1) is described. Applying both methods the death time estimation in the early postmortem interval may be much more precise and accurate than using one method alone.     

Estimation of short-term postmortem interval utilizing core body temperature: a new algorithm

The use of temperature-based short-term postmortem interval (PMI) estimation methods can be useful to homicide investigators at the scene of a questionable death; however, a number of current PMI estimation techniques have high error rates such that they are of limited utility to law enforcement investigators and forensic professionals. These methods fail to control confounding errors present in individual data. An averages-based method of short term postmortem interval estimation was compared to eight other methods, and found to predict postmortem interval considerably more accurately, and for much longer periods of time.     

Time since death and decomposition of the human body: variables and observations in case and experimental field studies

Much of the difficulty in determining the time since death stems from the lack of systematic observation and research on the decomposition rate of the human body. Continuing studies conducted at the University of Tennessee, Knoxville, provide useful information on the impact of carrion insect activity, ambient temperature, rainfall, clothing, burial and depth, carnivores, bodily trauma, body weight, and the surface with which the body is in contact. This paper reports findings and observations accumulated during eight years of research and case studies that may clarify some of the questions concerning bodily decay.     

Using accumulated degree-days to estimate the postmortem interval from decomposed human remains

Forensic anthropologists often rely on the state of decomposition to estimate the postmortem interval (PMI) in a human remains case. The state of decomposition can provide much information about the PMI, especially when decomposition is treated as a semi-continuous variable and used in conjunction with accumulated-degree-days (ADD). This preliminary study demonstrates a supplemental method of determining the PMI based on scoring decomposition using a point-based system and taking into account temperatures in which the remains were exposed. This project was designed to examine the ways that forensic anthropologists could improve their PMI estimates based on decomposition by using a more quantitative approach. A total of 68 human remains cases with a known date of death were scored for decomposition and a regression equation was calculated to predict ADD from decomposition score. ADD accounts for approximately 80% of the variation in decomposition. This study indicates that decomposition is best modeled as dependent on accumulated temperature, not just time.