Modelling the Thermodynamics of Maggot Masses during Decomposition

Estimating the minimum PMI (mPMI) based on larval age involves identifying the species, reconstructing the thermal history at a crime scene, and modelling the rate of development. However, few studies take into consideration the mass-generated heat produced by larvae co-existing in an aggregation. These localized increases in temperature are often highlighted in the literature as having an influence on larval development, but there are ongoing difficulties with incorporating this concept into mPMI estimates. This is mostly due to a lack of research on the topic, particularly with controlled laboratory experiments or in natural conditions simulations. The aim of this research was to determine whether heat generation varied in different sized aggregations and, if so, did it influence larval development and behaviour. Various sized aggregations (50-2500 larvae) composed solely of Lucilia sericata (Meigen, 1826)(Diptera: Calliphoridae) larvae were reared in the laboratory at a constant ambient temperature of 22 °C (±1 °C). Data loggers and a thermal imaging camera were used to record mass temperatures throughout the feeding stage of development. Larvae were sampled from these different sized aggregations at set times and had their instar determined and/or their lengths and fresh weights recorded so that developmental rates could be monitored. To investigate the movement of larvae as they fed in an aggregation, individuals were tagged with a fluorescing elastomer. These larvae were easily distinguished from the rest of the cohort, which allowed their positions within the mass to be recorded at regular intervals. The results showed a strong positive relationship between mass size and the amount of heat generated by the aggregation (p<0.001), with temperatures rising as masses increased in size. A minimum mass size of 1200 larvae was required for the local temperature to increase significantly above ambient, with aggregations of 2500 larvae producing temperatures that exceeded ambient by up to 14 °C (± 1.2 °C). Larvae sampled from increasingly large masses showed an accelerated rate of development during the 2nd and 3rd instar. This coincided with when masses were at their warmest. These faster growth rates resulted in larger aggregations entering the post-feeding phase of development an average of 13 hours earlier than smaller, cooler masses. Physical measurements taken from larvae at 70 hours development demonstrated that individuals sampled from larger masses were significantly longer and heavier than those sampled from smaller aggregations (p<0.001). This provided further evidence of faster growth rates. However, when compared to solitary larvae, all mass-reared larvae, regardless of the size of the aggregation, appeared to benefit from a faster rate of development, reduced mortality and larger body sizes at dispersal. Larvae were observed to be in a constant state of motion and continually repositioned themselves within the mass, rotating between the periphery and the centre where they presumably fed. The thesis highlights the need to incorporate mass temperatures into forensic casework when using larval development to estimate the time of death. Larvae sampled from large masses, particularly during the 3rd instar, could appear older than they actually are due to the accelerated rates of development experienced under warmer conditions. If this isn’t taken into consideration then it could result in an overestimation of the mPMI. Future research should focus on identifying how other variables influence heat generation in masses, as well as finding ways to estimate the size of a mass, and hence its thermal history, at a crime scene

The use of geoscience methods for aquatic forensic searches

There have been few publications on the forensic search of water and fewer still on the use of geoforensic techniques when exploring aqueous environments. Here we consider what the nature of the aqueous environment is, what the forensic target(s) may be, update the geoforensic search assets we may use in light of these, and provide a search strategy that includes multiple exploration assets. Some of the good practice involved in terrestrial searches has not been applied to water to-date, water being seen as homogenous and without the complexity of solid ground: this is incorrect and a full desktop study prior to searching, with prioritized areas, is recommended. Much experimental work on the decay of human remains is focused on terrestrial surface deposition or burial, with less known about the nature of this target in water, something which is expanded upon here, in order to deploy the most appropriate geoforensic method in water-based detection. We include case studies where detecting other forensic targets have been searched for; from metal (guns, knives) to those of a nonmetallic nature, such as submerged barrels/packages of explosives, drugs, contraband and items that cause environmental pollution. A combination of the consideration of the environment, the target(s), and both modern and traditional search devices, leads to a preliminary aqueous search strategy for forensic targets. With further experimental research and criminal/humanitarian casework, this strategy will continue to evolve and improve our detection of forensic targets

Geophysical monitoring of simulated homicide burials for forensic investigations

Finding hidden bodies, believed to have been murdered and buried, is problematic, expensive in terms of human resource and currently has low success rates for law enforcement agencies. Here we present, for the first time, ten years of multidisciplinary geophysical monitoring of simulated clandestine graves using animal analogues. Results will provide forensic search teams with crucial information on optimal detection techniques, equipment configuration and datasets for comparison to active and unsolved cold case searches. Electrical Resistivity (ER) surveys showed a naked burial produced large, low-resistivity anomalies for up to four years, but then the body became difficult to image. A wrapped burial had consistent small, high-resistivity anomalies for four years, then large high-resistivity anomalies until the survey period end. Ground Penetrating Radar (GPR) 110-900 MHz surveys showed the wrapped burial could be detected throughout. 225 MHz GPR data was optimal, but the naked burial was poorly imaged after six years. Results suggested conducting both ER and GPR surveys if the burial style was unknown when searching for interred remains. Surveys in winter and spring produced the best datasets, and, as post-burial time increases, surveying in these seasons became increasingly important. This multidisciplinary study provides critical new insights for law enforcement and families of the disappeared worldwide

The use of geoscience methods for aquatic forensic searches

There have been few publications on the forensic search of water and fewer still on the use of geoforensic techniques when exploring aqueous environments. Here we consider what the nature of the aqueous environment is, what the forensic target(s) may be, update the geoforensic search assets we may use in light of these, and provide a search strategy that includes multiple exploration assets. Some of the good practice involved in terrestrial searches has not been applied to water to-date, water being seen as homogenous and without the complexity of solid ground: this is incorrect and a full desktop study prior to searching, with prioritized areas, is recommended. Much experimental work on the decay of human remains is focused on terrestrial surface deposition or burial, with less known about the nature of this target in water, something which is expanded upon here, in order to deploy the most appropriate geoforensic method in water-based detection. We include case studies where detecting other forensic targets have been searched for; from metal (guns, knives) to those of a nonmetallic nature, such as submerged barrels/packages of explosives, drugs, contraband and items that cause environmental pollution. A combination of the consideration of the environment, the target(s), and both modern and traditional search devices, leads to a preliminary aqueous search strategy for forensic targets. With further experimental research and criminal/humanitarian casework, this strategy will continue to evolve and improve our detection of forensic targets

Monitoring of simulated clandestine graves of dismembered victims using UAVs, electrical tomography, and GPR over one year to aid investigations of human rights violations in Colombia, South America

In most Latin American countries there are significant numbers of missing people and forced disappearances, over 90,000 in Colombia alone. Successful detection of shallow buried human remains by forensic search teams is difficult in varying terrain and climates. Previous research has created controlled simulated clandestine graves of murder victims to optimize search techniques and methodologies. This paper reports on a study on controlled test site results over four simulated dismembered victims' clandestine graves as this is sadly a common scenario encountered in Latin America. Multispectral images were collected once post-burial, electrical resistivity surveys were collected 4 times and ground penetrating radar (GPR) surveys collected three times up to the end of the 371 day survey monitoring period. After data processing, results showed that the multispectral dataset could detect the simulated clandestine and control graves, with electrical resistivity imaging relative high resistances over some of the simulated graves but not over the empty control graves. GPR results showed good imaging on the Day 8 surveys, medium imaging on the Day 294 surveys and medium to good imaging on the Day 371 surveys. Study implications suggest that, whilst clandestine graves of dismembered homicide victims would likely result in smaller-sized graves when compared to graves containing intact bodies, these graves can still potentially be detected using remote sensing and geophysical methods

Health, education, and social care provision after diagnosis of childhood visual disability

Aim: To investigate the health, education, and social care provision for children newly diagnosed with visual disability.Method: This was a national prospective study, the British Childhood Visual Impairment and Blindness Study 2 (BCVIS2), ascertaining new diagnoses of visual impairment or severe visual impairment and blindness (SVIBL), or equivalent vi-sion. Data collection was performed by managing clinicians up to 1-year follow-up, and included health and developmental needs, and health, education, and social care provision.Results: BCVIS2 identified 784 children newly diagnosed with visual impairment/SVIBL (313 with visual impairment, 471 with SVIBL). Most children had associated systemic disorders (559 [71%], 167 [54%] with visual impairment, and 392 [84%] with SVIBL). Care from multidisciplinary teams was provided for 549 children (70%). Two-thirds (515) had not received an Education, Health, and Care Plan (EHCP). Fewer children with visual impairment had seen a specialist teacher (SVIBL 35%, visual impairment 28%, χ2p < 0.001), or had an EHCP (11% vs 7%, χ2p < 0 . 01).Interpretation: Families need additional support from managing clinicians to access recommended complex interventions such as the use of multidisciplinary teams and educational support. This need is pressing, as the population of children with visual impairment/SVIBL is expected to grow in size and complexity.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

Psychosocial impact of undergoing prostate cancer screening for men with BRCA1 or BRCA2 mutations.

OBJECTIVES: To report the baseline results of a longitudinal psychosocial study that forms part of the IMPACT study, a multi-national investigation of targeted prostate cancer (PCa) screening among men with a known pathogenic germline mutation in the BRCA1 or BRCA2 genes. PARTICPANTS AND METHODS: Men enrolled in the IMPACT study were invited to complete a questionnaire at collaborating sites prior to each annual screening visit. The questionnaire included sociodemographic characteristics and the following measures: the Hospital Anxiety and Depression Scale (HADS), Impact of Event Scale (IES), 36-item short-form health survey (SF-36), Memorial Anxiety Scale for Prostate Cancer, Cancer Worry Scale-Revised, risk perception and knowledge. The results of the baseline questionnaire are presented. RESULTS: A total of 432 men completed questionnaires: 98 and 160 had mutations in BRCA1 and BRCA2 genes, respectively, and 174 were controls (familial mutation negative). Participants' perception of PCa risk was influenced by genetic status. Knowledge levels were high and unrelated to genetic status. Mean scores for the HADS and SF-36 were within reported general population norms and mean IES scores were within normal range. IES mean intrusion and avoidance scores were significantly higher in BRCA1/BRCA2 carriers than in controls and were higher in men with increased PCa risk perception. At the multivariate level, risk perception contributed more significantly to variance in IES scores than genetic status. CONCLUSION: This is the first study to report the psychosocial profile of men with BRCA1/BRCA2 mutations undergoing PCa screening. No clinically concerning levels of general or cancer-specific distress or poor quality of life were detected in the cohort as a whole. A small subset of participants reported higher levels of distress, suggesting the need for healthcare professionals offering PCa screening to identify these risk factors and offer additional information and support to men seeking PCa screening

The search for “Fred”: an unusual vertical burial case

Police witness intelligence stated a murdered adult male “Fred” had been vertically buried in wooded hilly terrain 30 years ago in the Midlands, UK. Conventional search methods were unsuccessful; therefore, the Police requested a geophysical investigation to be undertaken to determine if “Fred” could be detected. A multi-phased geophysical approach was conducted, using bulk ground conductivity and metal detectors, then follow-up magnetics and GPR survey profiles on EM anomalous areas. A tight grid pattern was used to account for the reduced target size. Relatively high-resolution EM and GPR techniques were determined optimal for this terrain and sandy soil. Geophysical anomalies were identified and the most promising intrusively investigated, this was found to be a large boulder and tree roots. Study implications suggest careful multi-phase geophysical surveys are best practice and give confidence in cold-case searches. This study yielded a no-body result, effectively saving Police time and costs from further investigations