Improving the strategy to identify historical military remains: a literature review and Y-STR meta-analysis.

The identification of historical military remains by Unrecovered War Casualties-Army (UWC-A) currently relies on Y-chromosome Short Tandem Repeat (Y-STR) testing when maternal relatives are not available, or when a mitochondrial DNA match does not provide sufficient certainty of identification. However, common Y-STR profiles (using Yfiler™) between sets of remains or families often prevent identification. To resolve these cases, an investigation of additional Y-DNA markers is needed for their potential inclusion into the DNA identification strategy. The number of genetic transmissions between missing soldiers and their living relatives needs to be considered to avoid false exclusions between paternal relatives. Analysis of 236 World War I/II (WWI/II) era pairs of relatives identified up to seven genetic transmissions between WWII soldiers and their living relatives, and nine for WWI. Previous Y-STR meta-analyses were published approximately 10 years ago when rapidly mutating markers were relatively new. This paper reports a contemporary literature review and meta-analysis of 35 studies (which includes 23 studies not previously used in meta-analysis) and 23 commonly used Y-STR's mutation rates to inform the inclusion of additional loci to UWC-A's DNA identification strategy. Meta-analysis found mutation data for a given Y-STR locus could be pooled between studies and that the mutation rates were significantly different between some loci (at P < 0.05). Based on this meta-analysis, we have identified two additional markers from PowerPlex® Y23 for potential inclusion in UWC-A's identification strategy. Further avenues for potential experimental exploration are discussed. Key points: From 236 UWC-A pairs of relatives, we observed up to nine genetic transmissions between WWI soldiers and their living relatives, and seven for WWII.MedCalc® software for meta-analysis utilizing the Freeman-Tukey transformation was run, which analysed 35 published studies and 23 commonly used loci. Previous Y-STR mutation rate meta-analyses are now 10 years old; this paper includes 23 studies that were not included in previous meta-analyses.Through meta-analysis, we identify two markers from PowerPlex® Y23 for potential inclusion in UWC-A's historical remains identification strategy (alongside Yfiler™). We discuss potential next steps for experimental exploration of additional Y-DNA markers.

Bloodstain pattern analysis: Does experience equate to expertise?

Bloodstain pattern analysis (BPA) has long been accepted by courts as an area of expertise; however, that position has recently been challenged. The discipline has been criticized for limited empirical research into practitioner determination error rates and whether determinations require specialized knowledge/expertise, including whether practitioner experience level influences accuracy. This study attempted to address these knowledge gaps as they relate to bloodstain pattern recognition. The aims were twofold: to establish whether practitioners would outperform lay non-practitioners, and whether practitioner experience influenced accuracy and error in determinations. Comparisons of practitioner responses under three scenarios (forced, casework, and definitive) were also made to assess conservatism/certainty in pattern recognition. Participants (both BPA practitioners and non-practitioners) analyzed photographs of bloodstain patterns and made determinations of the broad bloodstain category and specific bloodstain pattern type. When forced to provide only a single response, practitioners identified bloodstain categories and patterns significantly more accurately than non-practitioners (p = 0.0001, p < 0.00001, respectively). Practitioner accuracy in bloodstain pattern recognition was positively associated with experience level (p = 0.0429) and this was consistent regardless of response scenario. Although no significant difference in practitioner accuracy was observed across response scenarios, practitioner conservatism/certainty varied significantly among the broad bloodstain category and specific pattern types. Overall, these results support bloodstain pattern recognition as an area of expertise and that practitioner experience positively influences accuracy. Based on these results, a series of recommendations were proposed aimed at further improving practices within the discipline to maximize accuracy and reliability of BPA evidence.

A comparison of three shoe sole impression lifting methods at high substrate temperatures.

Footwear impressions are a common form of evidence found at crime scenes, and the accurate recovery and recording of such impressions is critical for shoe sole comparison and identification. The lifting of shoe sole impressions from hot surfaces (>30°C/86°F) and in hot environments has received little attention in the literature, particularly in relation to the recovery of class and randomly acquired characteristics (RACs) required for accurate comparisons. This study addressed this knowledge gap by comparing the performance of three common impression lifters (gelatin, adhesive, and vinyl static cling film) at recovering shoe sole impressions in dust from hot flooring substrates. Dry origin dust shoe sole impressions were made on ceramic tile, galvanized metal, and laminated wood flooring using a shoe that possessed two RACs and five class characteristics present on the sole. Substrates were left in direct full sun for five hours during a summer day prior to lifting. Performance was measured by the proportion of RACs and class characteristics visible in each lifted impression. Results demonstrated that the vinyl static cling film tested performed poorly across all substrates, particularly for metal (23.8% marks recovered), including notable shrinkage of the lifted impression. In contrast, adhesive (~96% marks recovered over all substrates), and to a lesser extent gelatin (~85%), lifts were highly successful on hot substrates. These data suggest that adhesive lifts can consistently and accurately recover shoe sole impressions from hot substrates. This study contributes critical information for crime scene examiners to improve and expand evidence recovery in hot environments.

Detection of blood on clothing laundered with sodium percarbonate.

Laundering clothes with modern detergents containing sodium percarbonate can result in false negative results when certain presumptive and confirmatory tests are used to detect the presence of blood. This is problematic as blood evidence can be inadvertently overlooked and criminal activity concealed, simply by laundering bloodstained clothes in detergent. The aim of this research was to determine if the incidence of positive results using tetramethylbenzidine (TMB) reagent, luminol, Bluestar® Magnum, ABAcard® Hematrace® and RSID™-Blood was affected by treatment in hot and cold water, with and without the detergent, sodium percarbonate. This study identified that RSID-Blood consistently produced positive results irrespective of water temperature or the addition of sodium percarbonate. All other reagents returned positive results in the absence of sodium percarbonate, regardless of water temperature. The introduction of sodium percarbonate initiated negative results regardless of water temperature when testing with tetramethylbenzidine reagent, Bluestar® Magnum and ABAcard® Hematrace®. Luminol in the presence of sodium percarbonate responded differently to the temperature change of the water. Cold water returned positive results, however, hot water returned negative results. This research indicates that RSID™-Blood surpassed other blood screening tests identifying blood on sodium percarbonate treated cotton fabric. The results for luminol were varied depending on water temperature, however, luminol performed better as a presumptive test than TMB or Bluestar® Magnum.

A Comparison of Four Presumptive Tests for the Detection of Blood on Dark Materials.

Detection of blood on dark materials is difficult for crime scene examiners so presumptive tests are used to assist. This study compared the ability of luminol, leuko crystal violet, tetramethylbenzidine, and Combur Test®E to detect whole, diluted blood (1:100) and a key-shaped blood transfer stain (1:10), on dark cotton sheeting, tea towel, socks, synthetic carpet, and car mats. Powdered bleach was used to evaluate specificity of the blood detection tests. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall misclassification rate (OMR) assessed the quality of the blood tests. Luminol was the preferred test for diluted blood having the highest sensitivity (79%-96%), NPV (66%-93%), and the lowest OMR (3%-15%). Luminol was also found to be most efficient with a testing time on 25 items of 2 h 50 min compared with up to 8 h. Overall, luminol was the most effective method, also providing information on bloodstain patterns.

Tissue preservation in extreme temperatures for rapid response to military deaths.

Many deployable forensic capabilities, including those used by the Australian Defense Force (ADF), employ mobile battery-operated fridge/freezers for DNA sample preservation that are not suitable for rapid response application due to their size and weight. These fridge/freezers are expensive, require regular specialised maintenance, and have a set payload. A variety of transport media are successful preservatives for DNA samples, however, there is no research specifically targeted to their suitability for operational environments where temperatures exceed 50 °C. This research examined whether sodium chloride (NaCl), ethanol, and dimethyl sulfoxide (DMSO) could preserve muscle and bone samples (fresh and early decomposition) as effectively as refrigeration, when stored at 21 °C, 45 °C, 55 °C, and 65 °C for at least one week. A total of 78 muscle and 78 bone samples were collected from an unknown deceased individual. Half of each tissue type was stored at 30 °C for 48 h to induce early decomposition. Following this, samples were stored in the transport media for one week at the above temperatures, and a control set of samples were refrigerated (-4 °C) without any transport media. Preserved samples would need to provide DNA profiles comparable to the refrigerated samples for the transport media to be considered a successful replacement method. NaCl and 70% ethanol preserved muscle samples (fresh and decomposed) up to 65 °C, as well as 70% ethanol and 20% DMSO for fresh bone samples. These results were comparable with refrigeration and therefore, these preservatives could be used in rapid response operations by the military and for disaster victim identification. Conversely, under the conditions of this study, 20% DMSO and 70% ethanol failed to consistently produce full DNA profiles from decomposed bone, and NaCl performed poorly at preserving DNA from fresh and decomposed bone samples.

Validation of Bioelectrical Impedance Spectroscopy to Measure Total Body Water in Resistance-Trained Males.

The three-compartment (3-C) model of physique assessment (fat mass, fat-free mass, water) incorporates total body water (TBW) whereas the two-compartment model (2-C) assumes a TBW of 73.72%. Deuterium dilution (D2O) is the reference method for measuring TBW but is expensive and time consuming. Multifrequency bioelectrical impedance spectroscopy (BIS SFB7) estimates TBW instantaneously and claims high precision. Our aim was to compare SFB7 with D2O for estimating TBW in resistance trained males (BMI >25kg/m2). We included TBWBIS estimates in a 3-C model and contrasted this and the 2-C model against the reference 3-C model using TBWD2O. TBW of 29 males (32.4 ± 8.5 years; 183.4 ± 7.2 cm; 92.5 ± 9.9 kg; 27.5 ± 2.6 kg/m2) was measured using SFB7 and D2O. Body density was measured by BODPOD, with body composition calculated using the Siri equation. TBWBIS values were consistent with TBWD2O (SEE = 2.65L; TE = 2.6L) as were %BF values from the 3-C model (BODPOD + TBWBIS) with the 3-C reference model (SEE = 2.20%; TE = 2.20%). For subjects with TBW more than 1% from the assumed 73.72% (n = 16), %BF from the 2-C model differed significantly from the reference 3-C model (Slope 0.6888; Intercept 5.093). The BIS SFB7 measured TBW accurately compared with D2O. The 2C model with an assumed TBW of 73.72% introduces error in the estimation of body composition. We recommend TBW should be measured, either via the traditional D2O method or when resources are limited, with BIS, so that body composition estimates are enhanced. The BIS can be accurately used in 3C equations to better predict TBW and BF% in resistance trained males compared with a 2C model.

A new disaster victim identification management strategy targeting "near identification-threshold" cases: Experiences from the Boxing Day tsunami.

The international disaster victim identification (DVI) response to the Boxing Day tsunami, led by the Royal Thai Police in Phuket, Thailand, was one of the largest and most complex in DVI history. Referred to as the Thai Tsunami Victim Identification operation, the group comprised a multi-national, multi-agency, and multi-disciplinary team. The traditional DVI approach proved successful in identifying a large number of victims quickly. However, the team struggled to identify certain victims due to incomplete or poor quality ante-mortem and post-mortem data. In response to these challenges, a new 'near-threshold' DVI management strategy was implemented to target presumptive identifications and improve operational efficiency. The strategy was implemented by the DNA Team, therefore DNA kinship matches that just failed to reach the reporting threshold of 99.9% were prioritized, however the same approach could be taken by targeting, for example, cases with partial fingerprint matches. The presumptive DNA identifications were progressively filtered through the Investigation, Dental and Fingerprint Teams to add additional information necessary to either strengthen or conclusively exclude the identification. Over a five-month period 111 victims from ten countries were identified using this targeted approach. The new identifications comprised 87 adults, 24 children and included 97 Thai locals. New data from the Fingerprint Team established nearly 60% of the total near-threshold identifications and the combined DNA/Physical method was responsible for over 30%. Implementing the new strategy, targeting near-threshold cases, had positive management implications. The process initiated additional ante-mortem information collections, and established a much-needed, distinct "end-point" for unresolved cases.

The effect of fluid consumption on the forest workers' performance strategy.

The heart rate development and time consumption of four Zimbabwean forest workers engaged in manual harvesting were studied to assess their performance strategy and whether this strategy was affected by differences in fluid consumption. Each worker was studied during 8 consecutive working days and produced 2.4 m3 pulpwood/day. They consumed either 0.17 l or 0.6 l of water each 1/2 hour with one fluid scheme assigned to each day according to a randomised block (person) design with four replicates (days). All workers were found to harvest large trees at the start of the working day and small trees at the end. All workers took longer to complete their task when on the low fluid scheme, however, the effect on the heart rate development varied for the individual workers as the strategies adopted to accommodate the stress inflicted by the low fluid scheme, varied for the individual workers. It is recommended that sufficient fluid supply during work be accompanied by training of the workers to convey the need and benefits of sufficient fluid consumption.

Implications for DNA identification arising from an analysis of Australian forensic databases.

Previous analyses of Australian samples have suggested that populations of the same broad racial group (Caucasian, Asian, Aboriginal) tend to be genetically similar across states. This suggests that a single national Australian database for each such group may be feasible, which would greatly facilitate casework. We have investigated samples drawn from each of these groups in different Australian states, and have quantified the genetic homogeneity across states within each racial group in terms of the "coancestry coefficient" F(ST). In accord with earlier results, we find that F(ST) values, as estimated from these data, are very small for Caucasians and Asians, usually <0.5%. We find that "declared" Aborigines (which includes many with partly Aboriginal genetic heritage) are also genetically similar across states, although they display some differentiation from a "pure" Aboriginal population (almost entirely of Aboriginal genetic heritage).