DEET (N,N‐Diethyl‐meta‐toluamide) Induced Delay of Blowfly Landing and Oviposition Rates on Treated Pig Carrion (Sus scrofa L.)

Abstract: The question of whether the insect repellent N,N‐Diethyl‐meta‐toluamide (DEET) affected fly attraction, oviposition, and larval development was investigated; in part, to determine whether the common habit of wearing DEET as a repellent could affect the rate of human decomposition. Experiments using pig surrogates of human decedents were carried out in a rural environment. Dead piglets were sprayed with DEET, and fly behavior, colonization levels, and maggot development were compared with those in nonsprayed controls. Piglets treated with DEET experienced significant delays in fly visitation and oviposition and delayed appearance of each larval instar, as well as reduced total larval numbers (p < 0.01 for all variables), with subsequently reduced decomposition (p < 0.05). Such changes in fly behavior and larval population development would significantly impact the estimation of the period following the death from entomological evidence in decedents wearing DEET at the time of their death.     

The Biological Effects of Kambo: Is There a Relationship Between its Administration and Sudden Death?

Kambo is a substance obtained from the skin secretions of a frog, Phyllomedusa bicolor, popular in the Amazon region, which is administered via the transdermal route. We report a case of 42‐year‐old man found dead in his house. Near the corpse, a plastic box labeled as “Kambo sticks” was found. The man was a chronic consumer of Kambo and no previous pathology or genetic disease emerged in clinical history from the declaration of his general practitioner. Autopsy investigations and toxicological analysis were performed. The histopathological examination showed left ventricular hypertrophy. Toxicological screening was negative for ethanol and other drugs. Phyllocaerulein, phyllokinin, and deltorphin A were isolated from the Kambo sticks but, only deltorphin A was detected in blood sample. We describe the first forensic case of death associated with Kambo administration. We attempt to explain how its use could be related to the cause of sudden death in this case.     

Temperature‐Dependent Postmortem Changes in Human Cardiac Troponin‐T (cTnT): An Approach in Estimation of Time Since Death

Estimation of time of death is an indispensible requirement of every medico‐legal autopsy, but unfortunately, there is not a single method by which it could be determined accurately. This study focused on the temperature‐dependent postmortem degradation of cardiac troponin‐T and its association with postmortem interval (PMI) in human. The analysis involved extraction of the protein, separation by denaturing gel electrophoresis (SDS‐PAGE), and visualization by Western blot using cTnT‐specific monoclonal antibodies. The area of the bands within a lane was quantified by scanning and digitizing the image using Gel Doc (Universal Hood). The results indicate a characteristic banding pattern among human cadavers (n = 6) and a pseudo‐linear relationship between percentage of cTnT degradation and the log of the time since death (r > 0.95), which can be used to estimate the postmortem interval. The data presented demonstrate that this technique can provide an extended time range during which PMI can be more accurately estimated.     

The Interest of Postmortem Bacteriology in Putrefied Bodies

A 27‐year‐old man was found dead in an advanced decomposition stage at home. On external examination, his body showed petechial hemorrhages of the skin. At autopsy, petechial hemorrhages of the epicardium were found, but no sign of meningitis was detected. Toxicological investigations remained negative. Bacteriological conventional analyses showed no significant result. Neisseria meningitidis serogroup B was finally isolated on cerebrospinal fluid by a specific real‐time polymerase chain reaction. To our knowledge, there are no available data about the postmortem diagnosis of an infectious cause of death in a decomposed corpse. In such situations, the polymicrobial overgrowth usually hampers the interpretation of bacteriological conventional methods and questions their diagnostic value. Such molecular bacteriological approaches appear to constitute an important diagnostic tool for forensic scientists and should be widely processed in case of suspected infectious death or sudden death whatever the postmortem interval.     

Accidental Trauma Mimicking Homicidal Violence

Homicide investigations represent an important function of death investigators. Although recognizing nonobvious homicides is crucial, an equally important role involves the identification of cases that initially present as possible homicides, but are ultimately discovered to not represent homicides. Failure to recognize such cases results in wasted time, squandered resources, false allegations, and potential life‐altering consequences. The authors review a series of cases wherein initial investigation suggested a possibility that the deaths represented homicides. By carefully considering additional information, including scene findings, history, and postmortem examination, each was determined to represent an accidental traumatic death. In addition to highlighting the importance of recognizing accidental traumatic deaths that initially present as homicides, the cases serve to highlight the fact that forensic pathology cannot be practiced without knowledge of appropriate ancillary information. Although guarding against cognitive bias is important in all forensic disciplines, including forensic pathology, access to vital case‐related ancillary information is an essential component of practicing medicine as a forensic pathologist.     

The Infant Injury Database: A Tool for the Study of Injury Patterns in Medicolegal Investigations of Child Abuse

In 2012, the Harris County Institute of Forensic Sciences began prospectively collecting injury data from pediatric autopsies. These data and associated case information from 635 pediatric cases are archived in the Infant Injury Database (IID). This paper introduces the IID to the forensic community and demonstrates its potential utility for child abuse and infant fatality investigations. The database is intended to be a source of evidence‐based research for coroners/medical examiners and clinicians in the recognition and diagnosis of child abuse. RR estimates were employed to quantify the relationship between individual autopsy findings to trauma‐related and nontrauma‐related causes of death. For example, unsurprisingly, the RR of trauma cases with multiple injury types is significantly greater than other causes of death, but the RR results provide a quantitative representation of the relationship. ROC curve modeling of the presence/absence of various injury types performed well at discriminating trauma from other causes of death (AUC = 0.96).     

Variability and Similarity of Gait as Evaluated by Joint Angles: Implications for Forensic Gait Analysis

Closed‐circuit television (CCTV) footage is used in criminal investigations to compare perpetrators with suspects. Usually, incomplete gait cycles are collected, making evidential gait analysis challenging. This study aimed to analyze the discriminatory power of joint angles throughout a gait cycle. Six sets from 12 men were collected. For each man, a variability range VR (mean ± 1SD) of a specific joint angle at a specific time point (a gait cycle was 100 time points) was calculated. In turn, each individual was compared with the 11 others, and whenever 1 of these 11 had a value within this individual's VR, it counted as positive. By adding the positives throughout the gait cycle, we created simple bar graphs; tall bars indicated a small discriminatory power, short bars indicated a larger one. The highest discriminatory power was at time points 60–80 in the gait cycle. We show how our data can assess gait data from an actual case.     

Fluorescence Imaging of Posterior Spiracles from Second and Third Instars of Forensically Important Chrysomya rufifacies (Diptera: Calliphoridae),

Entomological protocols for aging blowfly (Diptera: Calliphoridae) larvae to estimate the time of colonization (TOC) are commonly used to assist in death investigations. While the methodologies for analyzing fly larvae differ, most rely on light microscopy, genetic analysis, or, more rarely, electron microscopy. This pilot study sought to improve resolution of larval stage in the forensically important blowfly Chrysomya rufifacies using high‐content fluorescence microscopy and biochemical measures of developmental marker proteins. We established fixation and mounting protocols, defined a set of measurable morphometric criteria and captured developmental transitions of 2nd instar to 3rd instar using both fluorescence microscopy and anti‐ecdysone receptor Western blot analysis. The data show that these instars can be distinguished on the basis of robust, nonbleaching, autofluorescence of larval posterior spiracles. High‐content imaging techniques using confocal microscopy, combined with morphometric and biochemical techniques, may therefore aid forensic entomologists in estimating TOC.     

Measurement of Postmortem Pupil Size: A New Method with Excellent Reliability and Its Application to Pupil Changes in the Early Postmortem Period

Measurement of postmortem pupil width is a potential component of death time estimation. However, no standardized measurement method has been described. We analyzed a total of 71 digital images for pupil–iris ratio using the software ImageJ. Images were analyzed three times by four different examiners. In addition, serial images from 10 cases were taken between 2 and 50 h postmortem to detect spontaneous pupil changes. Intra‐ and inter‐rater reliability of the method was excellent (ICC > 0.95). The method is observer independent and yields consistent results, and images can be digitally stored and re‐evaluated. The method seems highly eligible for forensic and scientific purposes. While statistical analysis of spontaneous pupil changes revealed a significant polynomial of quartic degree for postmortem time (p = 0.001), an obvious pattern was not detected. These results do not indicate suitability of spontaneous pupil changes for forensic death time estimation, as formerly suggested.     

Viability of Human Articular Chondrocytes Harvested Postmortem: Changes with Time and Temperature of In Vitro Culture Conditions

Different studies of long‐term chondrocytes viability have shown a gradual reduction as a function of time and ambient temperature. The aim of our in vitro study was to establish chondrocyte postmortem viability curves for 4°C, 11°C, 23°C, 35°C during 63 days after the donors' death. Osteochondral cylinders were procured from the knees of 16 male donors (20–47 years), stored in preservation media that was not changed, and analyzed in 3‐day intervals using a confocal laser scanning microscope. A significant influence of time on viability was found from Day 9 (p = 0.0029) and onwards (p < 0.0001). The lowest overall chondrocyte viability was at 35°C, followed by 4°C (p < 0.0001). The conditions used in this in vitro analysis suggest that similar viabilities may occur while in situ in the decedent. Further studies of chondrocyte viability from individuals with known postmortem intervals may show premise to help evaluate time since death in the late postmortem interval.     

Philemon and Baucis Deaths: Case Reports and Postmortem Biochemistry Contribution

The death of a person as a reaction to the death of another is known as Philemon and Baucis death and may represent a difficult challenge for pathologists, especially due to the decompositional changes that often characterized these situations. In this article, we describe two cases of Philemon and Baucis deaths, the first concerning a married couple and the second concerning a father and son. Postmortem investigations including radiology and biochemistry were performed. Based on the results of all investigations, deaths were attributed to natural causes. Third‐party involvement could be excluded in both situations. In one case, biochemical analysis results revealed potentially contributing causes of death. The reported cases emphasize the importance of correlating findings from different postmortem investigations to identify causes of death, precipitating conditions and predisposing disorders, thus allowing the conclusion of natural death to be reached and third‐party involvement to be excluded.     

The Need for an Interdisciplinary Approach in Forensic Sciences: Perspectives from a Peculiar Case of Mummification

The finding of a mummified body raises many problems, also because of the limits of the medico‐legal investigations in case of mummification. Psychological autopsy and behavioral analysis have demonstrated a significant impact in case of equivocal death. The mummified corpse of a woman was found sealed in a wardrobe during the death investigation of a 36‐year‐old man, later discovered to be the woman's son. The woman's corpse was well preserved and no external injuries were found. Autopsy could not ascertain the cause of death. The state of the premises and the writings on the walls offered an opportunity to investigate the man's psychological profile and to better understand how the events might have taken place. The role of an accurate investigative analysis of the crime scene is a cornerstone of forensic pathology and the case presented underlies the importance of an interdisciplinary approach in forensic sciences.     

An Unusually High Cocaine Blood Concentration in an Impaired Driving Investigation

Cocaine is an illicit drug frequently encountered by forensic practitioners in driving under the influence of drugs (DUID) casework. Whole blood collected from a suspected drugged driver was found to contain 3.000 mg/L cocaine, 1.600 mg/L benzoylecgonine, and 0.260 mg/L methamphetamine. The high concentration of cocaine, while common in overdose death investigations, is unusual for an impaired driving case. Information from the officer revealed that the motorist swallowed cocaine during the traffic stop. Although a cocaine DUID charge could not be pursued, the blood methamphetamine concentration exceeded the State of Nevada “per se” limit for operating a motor vehicle. The motorist was successfully prosecuted for DUID based on his admission of using methamphetamine prior to driving and the blood methamphetamine result. This case highlights the importance of considering case history when interpreting laboratory results and the application of jurisdictional statutes as an approach to prosecuting suspected drug‐impaired drivers.     

First Report of Blaesoxipha plinthopyga (Diptera: Sarcophagidae) from a Human Corpse in the U.S.A. and a New State Geographic Record Based on Specimen Genotype

Carrion flies in the taxonomic family Sarcophagidae are often recovered from a human corpse. However, because such specimens are difficult to identify, the forensic literature on this taxon is quite limited compared with that of the commonly employed Calliphoridae. Faced with a sarcophagid larva that could not be identified microscopically from a death investigation in the state of Idaho, we generated cytochrome oxidase one DNA sequence data from the specimen. Comparison to a reference data set of forensically significant sarcophagids from Canada and the U.S.A. confirmed that this was the first discovery of Blaesoxipha plinthopyga in a human corpse in the U.S.A. and the first record of this species in Idaho. Because B. plinthopyga occurs from the Northern U.S.A. to the Neotropics, it is potentially useful for estimating time since death at many locations.     

Application of MALDI‐TOF MS for Estimating the Postmortem Interval in Rat Muscle Samples

Estimating the postmortem interval (PMI) is very important in the forensic sciences. Although many approaches have been used for estimating the PMI, accurate PMI calculations are still difficult. In this study, four Sprague Dawley (SD) rats were sacrificed by suffocation, and muscle samples were collected by dissection at various time intervals (0, 48, 96, and 144 h) after death. All samples were probed using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) to obtain molecular images and data for principal component analysis (PCA). The results showed that the peaks at m/z 1511, 1543, 1564, 1586 clearly decreased in intensity from 0 to 144 h postmortem and that the time groups were separated from each other on the PCA score plot. The prediction model showed high recognition capability (95.93%) and cross‐validation (83.72%). Our work suggests that MALDI‐TOF MS can be used to determine the PMI.     

Internal Morphological Analysis for Age Estimation of Blow Fly Pupae (Diptera: Calliphoridae) in Postmortem Interval Estimation*

Abstract: Larvae and pupae of blow fly species are frequently used in postmortem interval estimation, their age indicating minimum time since death. Most studies have considered age estimation of larvae, neglecting study of pupae. Relative development of external pupal features is useful, but there are also internal changes during metamorphosis that may be indicators of age, utilizing histological techniques. This study aimed to optimize preservation and histological analysis of blow fly pupae, specifically Calliphora vicina Robineau‐Desvoidy and Lucilia sericata (Meigen), and to examine internal features with potential for age estimation. Effect of hot‐water‐killing and different preservatives were examined. It was determined that blow fly pupae should be pierced through the three tagma, hot‐water‐killed, and preserved in 80% ethanol as the optimal preservation for subsequent analyses. Hematoxylin and eosin stained pupal sections revealed differences in brain and thoracic muscle development throughout the pupal stage with potential for age estimation.     

The Role of Forensic Botany in Crime Scene Investigation: Case Report and Review of Literature

Management of a crime is the process of ensuring accurate and effective collection and preservation of physical evidence. Forensic botany can provide significant supporting evidences during criminal investigations. The aim of this study is to demonstrate the importance of forensic botany in the crime scene. We reported a case of a woman affected by dementia who had disappeared from nursing care and was found dead near the banks of a river that flowed under a railroad. Two possible ways of access to crime scene were identified and denominated “Path A” and “Path B.” Both types of soil and plants were identified. Botanical survey was performed. Some samples of Xanthium Orientalis subsp. Italicum were identified. The fall of woman resulted in external injuries and vertebral fracture at autopsy. The botanical evidence is important when crime scene and autopsy findings are not sufficient to define the dynamics and the modality of death.     

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.     

Ruptured Syphilitic Aneurysm: A Cause of Sudden Death in a Man with Human Immunodeficiency Coinfection

Syphilis, a sexually transmitted infection caused by the bacterium Treponema palladium, is experiencing a worldwide resurgence. The risk of syphilis infection is particularly high in men who have sex with men (MSM), especially those who are human immunodeficiency virus (HIV)‐positive. Untreated syphilis can lead to rare but severe late‐stage complications, including syphilitic aortitis. Herein, we present an autopsy case of a ruptured thoracic aneurysm that resulted from an undetected case of syphilitic aortitis in an HIV‐positive Japanese MSM with undiagnosed syphilis. Although no syphilitic skin lesions were observed on the body, anatomical changes consistent with a syphilitic etiology were present at the site of the rupture, including medial aortic scarring with “tree‐bark”‐like atherosclerotic plaque. In addition, heart blood was positive for T. palladium in a latex agglutination test. This case highlights for forensic pathologists the importance of recognizing syphilis as a possible underlying cause of sudden death among HIV‐positive MSM.