Experimental results on data analysis algorithms for extracting and interpreting edge feature data for duct tape and textile physical fit examinations

A physical fit is an important observation that can result from the forensic analysis of trace evidence as it conveys a high degree of association between two items. However, physical fit examinations can be time-consuming, and potential bias from analysts may affect judgment. To overcome these shortcomings, a data analysis algorithm using mutual information and a decision tree has been developed to support practitioners in interpreting the evidence. We created these tools using data obtained from physical fit examinations of duct tape and textiles analyzed in previous studies, along with the reasoning behind the analysts' decisions. The relative feature importance is described by material type, enhancing the knowledge base in this field. Compared with the human analysis, the algorithms provided accuracies above 90%, with an improved rate of true positives for most duct tape subsets. Conversely, false positives were observed in high-quality scissor cut (HQ-HT-S) duct tape and textiles. As such, it is advised to use these algorithms in tandem with human analysis. Furthermore, the study evaluated the accuracy of physical fits when only partial sample lengths are available. The results of this investigation indicated that acceptable accuracies for correctly identifying true fits and non-fits occurred when at least 35% of a sample length was present. However, lower accuracies were observed for samples prone to stretching or distortion. Therefore, the models described here can provide a valuable supplementary tool but should not be the sole means of evaluating samples.     

The Durability of Imposed Democracy

Why do imposed democracies endure and how do policy choices by imposing states affect durability? To study these questions, we formulate expectations linking durability to structural domestic conditions, the level of domestic security in the state into which a polity is imposed, the policies of imposing states, and the regional environment within which an imposed democracy is nested. We use event history to test our expectations on a sample of democracies imposed during the twentieth century. We find that relatively immutable, structural conditions, such as ethnic cleavages, economic development, and prior democratic experience strongly influence the durability of imposed democracies. While some policy choices made by imposing states can impact the survival of imposed democracy, they do so only modestly relative to the environment in which a democracy is imposed.     

Using Open-Source Data to Identify Participation in the Illicit Antiquities Trade: A Case Study on the Cypriot Civil War

The illicit trade in antiquities from conflict zones is clandestine and politicised and it very likely involves violent, organised criminals, including paramilitaries and terrorists; so reliable, detailed information is extraordinarily difficult to access. Nonetheless, open-source data may provide clues to the structure of the market. This article reviews the development of the Cypriot antiquities trade until the outbreak of the civil war in 1963, through the cultural heritage crisis that accompanied that conflict until the coup and invasion of 1974. Then, adapting an established method for studying the scale of a small, undisturbed illicit market, it gauges communities’ participation in looting during the civil war in Cyprus. It does so by analysing the find-spot and acquisition date information in collections of antiquities recovered before and during conflict, and cross-referencing them with demographic and historical information in order to identify the communities from which the looters probably came. It uses this crude categorical method in order to assess ethnically-based narratives of looting and trading in illicit antiquities. The evidence suggests that: before the conflict, there was no correlation between community and looting; during the civil war, due to economic and geopolitical factors, members of Turkish Cypriot communities were disproportionately involved in looting; at the same time, members of Greek Cypriot communities were far more involved in looting than has previously been recognised; Greek Cypriot archaeologists have misinterpreted the structure of the trade and consequently contributed to communalist policies and nationalist histories; and the antiquities policy of the Republic of Cyprus was one of the significant causes of the developments in the trade.     

Protecting Rural Church-Going Immigrant Women from Family Violence

Rural Latino immigrant women at risk of family violence may perceive churches as their only source of help. However, immigrant church leaders may be poorly equipped to address family violence in their congregations. This article describes a project designed to stimulate and support appropriate responses to family violence by rural immigrant churches, including those identified with conservative theological views on women. The primary goal was to provide rural Latino church leaders with culturally sensitive materials and resources they were willing to use with their congregations. We collaborated with local service providers who assisted in recruiting the church leaders for the pastors’ workshops where the resource materials were presented. Survey data indicated most of the pastors were receptive to the content and planned to incorporate it into their church work. Suggestions are made for future research on this culturally sensitive approach to addressing family violence in the immigrant community.     

Deterring Gang-Involved Gun Violence: Measuring the Impact of Boston’s Operation Ceasefire on Street Gang Behavior

Objectives

The relatively weak quasi-experimental evaluation design of the original Boston Operation Ceasefire left some uncertainty about the size of the program’s effect on Boston gang violence in the 1990s and did not provide any direct evidence that Boston gangs subjected to the Ceasefire intervention actually changed their offending behaviors. Given the policy influence of the Boston Ceasefire experience, a closer examination of the intervention’s direct effects on street gang violence is needed.

Methods

A more rigorous quasi-experimental evaluation of a reconstituted Boston Ceasefire program used propensity score matching techniques to develop matched treatment gangs and comparison gangs. Growth-curve regression models were then used to estimate the impact of Ceasefire on gun violence trends for the treatment gangs relative to comparisons gangs.

Results

This quasi-experimental evaluation revealed that total shootings involving Boston gangs subjected to the Operation Ceasefire treatment were reduced by a statistically-significant 31 % when compared to total shootings involving matched comparison Boston gangs. Supplementary analyses found that the timing of gun violence reductions for treatment gangs followed the application of the Ceasefire treatment.

Conclusions

This evaluation provides some much needed evidence on street gang behavioral change that was lacking in the original Ceasefire evaluation. A growing body of scientific evidence suggests that jurisdictions should adopt focused deterrence strategies to control street gang violence problems.     

Do bone elasticity and postmortem interval affect forensic fractographic analyses?

Forensic fractographic features of bone reliably establish crack propagation in perimortem injuries. We investigated if similar fracture surface features characterize postmortem fractures. Experimentally induced peri- and postmortem fractures were used to assess if fractographic features vary as bone elasticity decreases during the postmortem interval (PMI). Thirty-seven unembalmed, defleshed human femoral shafts from males and females aged 33–81 years were fractured at varying PMIs with a drop test frame using a three-point bending setup and recorded with a high-speed camera. Vital statistics, cause of death, PMI length, temperature, humidity, collagen percentage, water loss, fracture energy, and fractography scores were recorded for each sample. Results showed that fractographic features associated with perimortem fractures were expressed in PMIs up to 40,600 accumulated degree hours (ADH), or 60 warm weather days. Hackle was the most consistently expressed feature, occurring in all fractures regardless of ADH. The most variable characteristics were wake features (78.4%) and arrest ridges (70.3%). Collagen percentage did not correlate strongly with ADH (r = −0.04, p = 0.81); however, there was a strong significant correlation between ADH and water loss (r = 0.74, p < 0.001). Multinomial logistic regression showed no association between fractographic feature expression and ADH or collagen percentage. In conclusion, forensic fractographic features reliably determine initiation and directionality of crack propagation in experimentally induced PMIs up to 40,600 ADH, demonstrating the utility of this method into the recent postmortem interval. This expression of reliable fractographic features throughout the early PMI intimates these characteristics may not be useful standalone features for discerning peri- versus postmortem fractures.     

When national symbols divide: the case of pan-Catalanism and the Països Catalans

Shared symbols are an essential element in nationalist mobilisation. National symbols provide perhaps the strongest, clearest statement of national identity and are socially constructed. The effectiveness of these symbols will determine the success or failure of a political and cultural project. The effectiveness of cultural and political symbols can be seen through examination of the project of pan-Catalanism, the Països Catalans (the Catalan-speaking countries). This political project is rather unusual in the nationalist literature in being unable to advance beyond an embryonic stage. While cultural affinity can be determined within the Catalan-speaking territories, a wider claim to pan-Catalan political identity has foundered. This article argues that the absence of a shared attachment to national symbols in Catalonia, Valencia, the Balearics and other Catalan-speaking areas, provides the principal explanation why successful nation building has not been achieved.     

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, U.K. Conventional search methods were unsuccessful; therefore, the police requested a geophysical investigation to be undertaken to determine whether “Fred” could be detected. A multiphased geophysical approach was conducted, using bulk ground conductivity and metal detectors, then follow‐up magnetics and ground penetrating radar (GPR) survey profiles on electromagnetic (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, and this was found to be a large boulder and tree roots. Study implications suggest careful multiphase 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.