Identification of some factors influencing soil transfer on shoes

In criminal activities, soil can be transferred from a crime scene to items linked with a perpetrator; for example, shoes, cars or tools. Several parameters will influence the quantity of soil transferred in a given scenario. The knowledge of the most influential factors can help the expert to assess the evidence using a logical approach at the activity level or to predict the amount of soil that can be expected in a given scenario. The influence of five chosen parameters, namely the shoe profile, shoe size, walker's weight, soil type and soil humidity were assessed using Design of Experiment (DOE) in order to understand their influence on soil quantity transferred on shoes.The Faced Central Composite Design (FCCD) using a quadratic model was found to be highly significant, thus they could be adequately used to model and to interpret the amount of soil recovered from one shoe.These designs demonstrate that the characteristics of the donor (soil type and soil humidity), as well as a combination of these two factors have a very significant impact on the soil transfer. The characteristics of the receptor (shoe profile, shoe size and walker's weight) also have an impact on the transfer but to a lesser extent.Globally, this research provides valuable information for the forensic scientist both in investigative mode: evaluation of the soil quantity possibly transferred on shoes, and in the evaluative steps: is the quantity of soil found on the suspect shoes in accordance to the proposition/scenario given by the prosecution and the defence?     

Returning to the child welfare system: Understanding the wellbeing,health, education,and placement of children who return

Using longitudinal archival Child Welfare System (CWS) data, this study describes child health and wellbeing at their initial entrance into the CWS and subsequent returns. Associations between child wellbeing, health, placement stability, and frequency of returning to the system were also investigated. Results indicated most children were healthy and developmentally on target. In addition, emotional distress, behavioral concerns, and number of placements in the CWS were significantly correlated with placement stability. Future work should utilize the use of developmental assessments to systematically and reliably document the concerns for children in the system, and investigate factors contributing to stable placements.