The polymorphism of crime scene investigation: An exploratory analysis of the influence of crime and forensic intelligence on decisions made by crime scene examiners

Forensic intelligence in Australia and New Zealand: Status and future directions

Forensic science is underutilised. Operating models restricted to the support of court outcomes do not address core requirements of contemporary policing and public security, which are to disrupt criminal activity and prevent crime. Forensic intelligence (FORINT) is a principal means of enhancing the role of forensic science, emphasising proactivity and cross-case, cross-crime domain insights. To catalyse implementation, a FORINT Specialist Advisory Group (SAG) has been established under the Australia & New Zealand Policing Advisory Agency (ANZPAA) National Institute of Forensic Science (NIFS). The SAG has established a concept of operations with four lines of effort - namely, to (i) promote awareness and consistency, (ii) shape the workforce, (iii) develop information management frameworks and (iv) guide operational implementation. This aims to shift Australia & New Zealand from its present state (of substantial interagency variability) to a state of widespread, consistent and effective FORINT delivery in terms of: (a) culture, (b) information management, (c) education & training, and (d) organisation & operating environment. There are risks to implementing FORINT, in terms of privacy/confidentiality, bias/misinterpretation, and resource impost. However, these are not necessarily FORINT-specific, and solutions or mitigations exist. Moreover, these issues are outweighed by the risks of not implementing FORINT - such as a failure to reveal threats, missed opportunities, and poor resource efficiency. This paper is a call to arms. For policing and laboratories - now is the time to implement and entrench FORINT. For academia - now is the time to build foundations for this future. For supporting industries - now is the time to develop partnerships and facilitate delivery.

Transfer and persistence of microbiota markers from the human hand to the knife: A preliminary study

New scientific techniques and methods are always needed to link the perpetrators to the incident or the crime scene. Recent microbiota studies based on NGS (Next-generation sequencing) show that various biological samples from crime scenes have the potential to be used in forensic investigations. Especially when DNA traces belonging to more than one person are insufficient to fully determine the genetic profile, a secret sample, such as a microbiota sample created by the suspect's touch, can be used. In this preliminary study, a fictionalized experimental model was designed to investigate the transfer and persistence of the hand microbiome on the knife handle, which has a high potential to be used in criminal incidents, by metagenomic analysis methods. In addition, it was aimed to determine the transfer of specific bacterial species identified only to the person among the five participants onto the knife handle and their persistence over time. In the first stage of the research, samples were collected from the hands of 5 volunteer participants using the swap method, including their palms. Then, after each participant held a different knife, samples were collected from the knife handles via swabs from different angles of the knives at 4 and 24 h and analyzed by metagenomic methods. The findings of this preliminary study showed that the heatmap graphs generated after UniFrac distance analysis were not successful in establishing any similarity between the hand samples and the post-transfer knife handle samples. Nonetheless, it was observed that the transfer of bacterial species detected in the hand samples to knives differed according to the individuals and some bacterial species were transferred to the knife samples held by the participants. The number of bacterial species detected that are specific to each participant's hand sample was 302 in total, and it was determined that a total of 8.28 % of these bacterial species were transferred to the knife handle samples of the 4th hour and 6.95 % to the knife samples of the 24th hour. In the presented study, considering the transfer of some bacterial species in the hand microbiome, which are effective in the variation between individuals, onto the knife; It has been evaluated that some rare bacterial species can be important potential markers to associate the object with the perpetrator.

CSI-CSI: Comparing several investigative approaches toward crime scene improvement

Crime scene investigations are highly complex environments that require the CSI to engage in complex decision-making. CSIs must rely on personal experience, context information, and scientific knowledge about the fundamental principles of forensic science to both find and correctly interpret ambiguous traces and accurately reconstruct a scene. Differences in CSI decision making can arise in multiple stages of a crime scene investigation. Given its crucial role in forensic investigation, CSI decision-making must be further studied to understand how differences may arise during the stages of a crime scene investigation. The following exploratory research project is a first step at comparing how crime scene investigations of violent robberies are conducted between 25 crime scene investigators from nine countries across the world. Through a mock crime scene and semi-structured interview, we observed that CSIs have adopted a variety of investigation approaches. The results show that CSIs have different working strategies and make different decisions when it comes to the construction of relevant hypotheses, their search strategy, and the collection of traces. These different decisions may, amongst other factors, be due to the use of prior information, a CSI's knowledge and experience, and the perceived goal of their investigation. We suggest the development of more practical guidelines to aid CSIs through a hypothetico-deductive reasoning process, where (a) CSIs are supported in the correct use of contextual information, (b) outside knowledge and expertise are integrated into this process, and (c) CSIs are guided in the evaluation of the utility of their traces.

"Blood, Bucks and Bias": Reliability and biasability of crime scene investigators' selection and prioritization of blood traces

When crime scene investigators (CSIs) encounter crime scenes with large volumes of blood, some selection and prioritization is often needed, and this will impact on what blood is and is not available for forensic analysis. What factors influence CSIs decision making process is largely unknown. This study examines the effects of awareness of limited resources and irrelevant contextual case information indicating either a homicide or a suicide on CSIs collection of blood traces. To this end, two scenario-based experiments with CSIs and novices were conducted. Overall, the results suggest that even when CSIs decisions are made under identical conditions, their trace selection varies both when it comes to numbers and locations. Furthermore, awareness of limited resources made CSIs collect fewer traces and their selections also varied following the contextual case information, showing similarities and differences with novices. Since blood traces can be used to establish both activity and identity the findings can have important implications for the subsequent investigation as well as trial.

Sexual homicide and the forensic process: The decision-making process of collecting and analyzing traces and its implication for crime solving

The focus of the current study is to examine the collection and analysis of traces that are related to crime scene behaviors in sexual homicide cases as well as the factors influencing the solving of these crimes. Using 230 sexual homicide cases from the SHielD database, we computed two neural network models based on the multi-layer perceptron algorithm. First, we determined whether certain crime scene characteristics predicted the collection and analysis of traces (dependent variable for Model 1). Not surprisingly, the results indicate that trace collection and analysis were more likely to occur in sexual homicide cases with crime scene behaviors exhibiting the highest risk for trace transfer (e.g. close interactions with the victim) as well as the best conditions for trace persistence (e.g. body is found indoors). Situational and physical aspects of the crime scene are thus taken into account when deciding on the collection and analysis of traces. Second, we examined the situations in which the collection and analysis of traces contributes to crime solving (dependent variable for Model 2). The results suggest that the collection and analysis of traces does not necessarily predict the resolution of the case. Specifically, the analyses show that the collection and analysis of traces is useful for crime solving when: (1) the offenders' behaviors increase the opportunities for leaving traces at the crime scene, and (2) when the environmental and temporal aspects are favorable to the collection of traces. The impact of trace collection and analysis on case resolution is thus depending on the context of the case. Furthermore, the subsequent steps, such as the result of the trace analysis, the introduction into a database, the obtention of a result from this comparison, etc. might also affect case resolution, and thus interfere in the link between trace collection and analysis and case resolution.

The trace in the technique: Forensic science and the Connoisseur's gaze

Both scientific art investigations and forensic investigations rely on observation, inferential reasoning, and analytical techniques to answer questions concerning identification, source, and activity. The forensic scientist and the art connoisseur evaluate the whole—a crime scene or work of art, respectively—and draw meaning from the often-overlooked details, or traces, contained therein. This manuscript considers the correlations between art connoisseurship and forensic science, first by outlining the history of connoisseurship, focusing on the detection and evaluation of traces through patient observation, reasoning, and comparison based on methods established by Giovanni Morelli in the nineteenth century. This article then explores connoisseurship and forensic science within the historical sciences framework, based on the process in which observable traces can be ordered to provide a reconstruction of unobservable past events. Finally, this article asserts that art can be used to shape and refine the scientist's practiced eye, thereby improving trace detection and interpretation in investigations.

Management of crime scene units by Quebec police senior managers: Insight on forensic knowledge and understanding of key stakeholders

What do policing leaders think and know of forensic science? Beyond crime scene investigators or detectives, how do police senior managers perceive the role, utility and limitations of forensic science? Very few empirical studies have addressed the issue. Forensic scientsts should be concerned about the perception that law enforcement senior managers have of their discipline for two reasons. First, strategic and financial decision-makers are obviously key players in the overall administration and provision of forensic science, either as a supervisor, money provider or as a customer. Second, literature has highlighted that other actors involved in forensic science underestimate the scope and possibilities offered by forensic science, hence limiting its exploitation and potential. Following interviews with 18 police senior managers from Quebec (Canada), this study shows that they generally restrict forensic science to a reactive discipline whose role and utility is to identify offenders and support the Court. This understanding of forensic science, like that of many others including a significant share of forensic scientists, differs from the perception of other police activities in modern law enforcement agencies where proactive action is sought. Considering these findings and the growing body of literature which calls for forensic science to connect more tightly with policing and security, we advocate a more extensive education of police leaders regarding the scope of forensic science.

Homicide or car accident: The case of the 'guilty' fibre

Crime scene investigation should be carried out using a critical forensic approach by an expert team. This provides essential tools in the research and collection of evidence and samples which must be integrated with the autopsy and the police officers' investigations. This paper aims to highlight the importance of a multidisciplinary approach to crime scene investigation and describes a very interesting criminal case. As demonstrated by this case, the evidence obtained from the crime scene analysis sheds light on difficult cases, such as murders staged as suicides or accidents.