A forensic geoscience framework and practice

Appropriate and correct collection, analysis, interpretation, and presentation of geoforensic evidence are contingent upon understanding the specific context of the particular forensic investigation undertaken. To achieve this, the role of experimental studies in forensic geoscience must not be underestimated. In this article, we present two experimental studies that assess the spatial distribution of pollen in a living room and the nature of subsequent transfer of pollen onto clothing. The presence of cut flowers in a living room are shown to lead to a distribution of pollen grains onto all types of surface in that room that exhibits a distance–decay pattern with the greatest numbers of grains found in close proximity to the flowers. Once the transfer of pollen grains from a source location onto clothing has taken place, our second study demonstrates the nature of the persistence of that evidence for dry and damp clothing under active and inactive conditions. The level of activity after transfer is shown to have far more influence upon the persistence of this form of geoforensic evidence in comparison to the damp or dry conditions of the garment. We argue that these findings have implications for all stages of the forensic investigation–from sampling protocols to the interpretation of the presence/absence of geoforensic evidence. Whilst every contact does indeed leave a trace, it is imperative that there is an appreciation of the context of each forensic investigation, meaningful science take place and accurate and helpful crime reconstructions to be achieved

The relevance of the evolution of experimental studies for the interpretation and evaluation of some trace physical evidence

In order for trace evidence to have a high evidential value, experimental studies which mimic the forensic reality are of fundamental importance. Such primary level experimentation is crucial to establish a coherent body of theory concerning the generation, transfer and persistence of different forms of trace physical evidence. We contend that the forensic context, at whatever scale, will be specific to each individual forensic case and this context in which a crime takes place will influence the properties of trace evidence. it will, therefore, be necessary in many forensic cases to undertake secondary level experimental studies that incorporate specific variables pertinent to a particular case and supplement the established theory presented in the published literature. Such studies enable a better understanding of the specific forensic context and thus allow More accurate collection, analysis and interpretation of the trace physical evidence to be achieved. This paper presents two cases where the findings of secondary level experimental studies undertaken to address specific issues particular to two forensic investigations proved to be important. Specific pre-, syn- and post-forensic event factors were incorporated into the experimental design and proved to be invaluable in the recovery, analysis and in achieving accurate interpretations of both soil evidence from footwear and glass trace evidence from a broken window.These Studies demonstrate that a fuller understanding of the specific context within which trace physical evidence is generated and subsequently collected, as well as an understanding of the behaviour of certain forms of trace physical evidence under specific conditions, can add evidentiary weight to the analysis and interpretation of that evidence and thus help a court with greater certainty where resources (time and cost) permit

Sipho Gongxeka’s Skeem’ Saka: composing masculinity and protest in contemporary Soweto

Skeem’ Saka, a series of photographs by Sipho Gongxeka, reflects upon contemporary young black masculinity in Soweto. Produced between 2013 and 2014 under the umbrella of the Market Photo Workshop in Johannesburg, these photographs of South African men posing for the camera challenge an essentialist reading of selfhood. Incorporating musical and cinematic references, Skeem’ Saka questions masculinity and its representations. Simultaneously nourished by music, cinema and a contemporary feeling of nostalgia, the kwaito singer and the figure of the gangster appear as two paradoxical masculine tropes shaping the content of the series and its ‘compositional’ character. Their celebration in the series Skeem’ Saka opens up the question of formation of subjectivities, as well as the compound inflexions surrounding authenticity, homosociality and social mobility in Soweto. South Africa’s socio-political climate and contemporary visual culture have primarily been apprehended in terms of divisions. This paper will offer an alternative reading of masculinity and rebellion by highlighting Skeem’ Saka’s multiple fields of representation. Considering the cultural and political landscape in which this photographic series operates, I will argue that the figuration of masculinity as represented in Skeem’ Saka is intrinsically embedded in a generational claim

Rationalisation of Profiles of Abstract Argumentation Frameworks

International audienceDifferent agents may have different points of view. This can be modelled using different abstract argumentation frameworks , each consisting of a set of arguments and a binary attack-relation between them. A question arising in this context is whether the diversity of views observed in such a profile of argumentation frameworks is consistent with the assumption that every individual argumentation framework is induced by a combination of, first, some basic factual attack-relation between the arguments and, second, the personal preferences of the agent concerned. We treat this question of rationalisability of a profile as an algorithmic problem and identify tractable and intractable cases. This is useful for understanding what types of profiles can reasonably be expected to come up in a multiagent system