Masters Of Forensic Science Thesis - Murdoch University

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Masters of Forensic Science Thesis Development of a Good Practice Frameworks in Forensic Science Research By Cecilia Jepchumba Tanui A thesis submitted in fulfilment of the requirements for the degree of Master of Forensic Science (Professional Practice and Research) in The School of Veterinary and Life Sciences Murdoch University Supervisors Associate Professor James Speers (Murdoch) Dr Shane S. Tobe (Murdoch) Semester 1, 2 of 2019 i

Declaration I declare that this thesis does not contain any material submitted previously for the award of any other degree or diploma at any university or other tertiary institution. Furthermore, to the best of my knowledge, it does not contain any material previously published or written by another individual, except where due reference has been made in the text. Finally, I declare that all reported experimentations performed in this research were carried out by myself, except that any contribution by others, with whom I have worked is explicitly acknowledged. Signed: ii

Acknowledgments I want to show my gratitude to my supervisors Ass. Prof James Speers and Dr Shane Tobe for sharing their pearls of wisdom with me during this research. I would like to appreciate my classmates who have walked this long postgraduate journey with me. I also note the great support I have had from my family who have been instrumental in creating a conducive environment for me to work on this research. iii

Table of Contents Title Page . i Declaration .ii Acknowledgements . iii Part One Literature Review Part Two Manuscript 1

2

Part One Literature Review Development of a Good Practice Frameworks in Forensic Science Research 3

Abstract This paper focuses on the current best practices in the research methodology in the medical/ biomedical and biosciences disciplines and based on their recommendations and practices, developing best practice frameworks in forensic science research. Robust procedures have been identified and tested against several forensic papers that have been recently published to prove if they meet the selected criteria. The study will access the information acquired from previous forensic research papers and express the expectations of ideal forensic research, and this will lead to the development of a forensic framework that can be applied by researchers in different forensic disciplines. The idea that most of the forensic publications lack adequate scientific foundation is a critical issue that needs to be addressed to improve the validity and reliability of conclusions made in forensic science research. The 2009 National Academy of Sciences report Strengthening Forensic Science in the United States: A Path Forward pointing out the unscientific state of various forensic subfields has a clear indication of a knowledge gap regarding the reliability of the methods used in the research process61. The President’s Council of Advisors on Science and Technology62 report in 2016, has reviewed the matter and made recommendations for further progress in the challenges facing forensic science. The conclusion addresses the importance of developing forensic research culture that follows the selected procedures aimed at improving forensic science research. 4

Table of Contents Abstract .4 List of Figures .7 List of tables .7 List of Abbreviations .8 Introduction.9 Research Questions .9 Hypothesis .11 Null hypothesis .13 Alternate hypothesis.13 Experimental design .13 Variables .14 Dependent variable .15 Independent variable.15 Controlled variable .15 Samples .16 Data analysis .17 Controls .17 Discussion .18 Fingerprints .19 DNA .27 Entomology .33 Toxicology .39 Blood Pattern Analysis .56 Conclusion .58 Recommendations .60 Keywords .69 Table of Figures .72 List of Abbreviations .73 Introduction .74 Method .75 Results and Discussion .81 Research question .82 Hypothesis .83 Experimental design .85 Variables .86 5

Samples .87 Data analysis .88 Controls .89 Standards .90 Summary addressing the research question .91 Additional findings .93 Statistical ANOVA Analysis .95 Group 1: Disciplines .95 Group 2: Journals .97 Group 3: Years of Publication .99 ANOVA Results in Discussion .100 The limitations of the study. .101 Future directions.101 Conclusion.102 References .103 6

List of Figures Figure 1 Dependent and Independent Variables . 15 Figure 2 Graph analysis of the findings. 60 List of tables Table 1 Analysis of Findings . 57 7

List of Abbreviations DNA: Deoxyribonucleic Acid PCAST: President’s Council of Advisors on Science and Technology NAS: National Academy of Sciences STR: Short Tandem Repeat PCR: Polymerase Chain Reaction UV: Ultraviolet CAN: Cyanoacrylate GC-HRMS: Gas Chromatography-High Resolution Mass Spectrometry MIP: Molecular Inversion Probe 8

Introduction The Validity, credibility, and reliability of forensic science practice are significantly dependent on a robust research base. The scientific community has acknowledged that the scientific foundation of some of the present forensic methods requires strengthening. This strengthening can be achieved through continuous research programs designed to advance the reliability and validity of the available techniques and improve the development and usage of current and better techniques1. It is important to note that deficient forensic techniques which arise because of poor laboratory techniques, unsupported assumptions are the result of the initial poor research techniques3. Several robust scientific components if incorporated into forensic research, would improve it significantly. Some of the elements include; Research questions, hypothesis, samples, variables, experimental design, data analysis, and controls. Research Questions The research question is the aim of the study and the uncertainty that the researcher wants to resolve. Research questions begin with a general concern and narrow down to a real researchable issue2. Identification of the research question is the essential aspect of forensic research because it sets the framework of analysis. It should emerge from the title, result or findings and observed problems from the previous studies. The questions can be divided into more specific objectives that will consequently lead to more precise methods and definition of essential terms. The goals should be measurable, specific, time-framed, realistic, and achievable and should cover the complete scope of the research4. Developing a research question supported by relevant hypothesis, aims, and objectives is an essential crucial step towards producing relevant results needed for evidence-based practice. 9

A specific and well-defined research question provides guidance in decision making regarding the study design as well as the population and consequently provides an insight into the data to be collected and analysed2. The first step towards the development of a research question involves familiarity with the subject. These questions arise from the perceived knowledge within the area of study. It is important to note where the boundary between the current knowledge and ignorance lies. Therefore the need to know and understand best practice in research methodology is crucial, and this will aid the researcher in developing the appropriate research question and determine the uncertainties to be studied8. There are several ways that a researcher can increase knowledge. These ways include schematically searching the literature, in-depth interviews, and focus groups and interviews with experts in the field8. These methods help in the increase of knowledge within the particular study area. The literature review helps a scientist to identify the gaps which exist and also get an idea about what other previous researchers have studied concerning the topic. Forensic scientists should embrace this culture, and it will improve the results they will obtain in their research process8. Additionally, awareness of current trends and technological advances can assist with the development of research questions. It is a necessity to be aware of technological advancements to develop proper research questions2. In-depth knowledge also helps a researcher to know how many studies need to be conducted whether only one review will be sufficient to answer the questions or will more than one study be required. This practice will ensure that the research has been undertaken to completion. 10

For proper scientific research, the researcher should keep in mind that within the scope of one study the presence of several research questions will affect and potentially increase the complexity of both the study design and subsequent statistical analyses, not to mention the actual feasibility of answering every question7. Therefore it would be prudent to establish a single primary research question around which to focus the study plan. Several published legal papers have failed because of the presence of many research questions. When this happens, the study becomes very complicated, and the chances of encountering errors are increased. In summary, the fundamental research question should be clearly stated at the end of the introduction of the proposal, and it usually specifies the population to be studied, the intervention to be implemented and other detailed factors. A good research question should determine the population of interest, be of interest to the scientific community and potentially to the public, have clinical relevance and further current knowledge in the field 7. Hypothesis In any scientific study, it is essential to have hypothesis-driven research. However, since this is not always possible, there is the need for a null hypothesis, this is achieved mainly through the formulation of hypothesis. This prediction is usually stated in a complete sentence; it uses the observations made before the test to make an educated assertion. A hypothesis is a statement communicating what needs to be proved or disproved through a study7. Scientific research methods involve identification of a problem, gathering of relevant data, formulation, and testing of the hypothesis. This process first consists of a scientist seeing or identifying an issue related to the observation made. A hypothesis is then created to explain the inspection and make predictions. The predictions are then tested by experiment, or further observation 11

is further performed under controlled conditions4. At the end of the operation, the researcher will have to use the results to decide if he can accept the hypothesis or reject it. The hypothesis must stand up to questioning during the experiment. The hypothesis can be approved or disproved through an experiment4. Hypothesis testing maximises the reliability of research findings and contributes to the reproducibility of results8. Appropriate use of exact scientific procedures leads to the strengthening of inferences and reducing the potential for drawing spurious conclusions. Consequently, rigorous science by researchers contributes to development in their scientific knowledge and building credibility for their work. The hypothesis ought to be transparent because unclearly stated hypotheses may lead to misinterpretation of results 6. Majority of the research studies in forensic science are suffering from problems such as inadequate hypotheses, using data that does not represent casework conditions and tests on the same data as explained in the PCAST report 201662. Ideally, any research process should begin with a testable hypothesis that may be proved or disapproved at the end of the experiment8. A poorly defined hypothesis is a recipe for wrong results. Additionally, the hypothesis should be realistic and also needs to put into consideration the methods and technology available. Forensic scientists should look out for the simplest possible explanation for a natural occurrence or phenomena since it is the central underlying principle and tool for establishing recognised proofs4 to improve the process of suitable hypothesis formulation 12

There are two types of hypothesis: Null hypothesis The null hypothesis represents a theory that has been put forward, either because it is believed to be accurate or because it is to be used as a basis for argument but has not been proved. It is the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error. This kind of hypothesis has severe outcome if an incorrect decision is made. For this, the null hypothesis must be formulated very keenly. Alternate hypothesis The alternative hypothesis is a statement of what a hypothesis test is set up to establish. The alternate is the opposite of the Null Hypothesis. It is only reached if H0 is rejected7. In many circumstances, the alternate hypothesis is the desired conclusion of the researcher. Proper formulation of hypotheses is a basis for relevant scientific research. Experimental design The research design ought to be able to address the research questions. It ranges from observational to experimental, allowing scientists to gather suitable data to support or reject the hypothesis11. From the preliminary designs, scholars can be able to test whether their interpretations are correct2. Even though these scientists can draw a countless variety of innovative designs, most laboratory experiment, share one important characteristic. Suitable design in research should be one that minimises bias while maximising the reliability of the collected and analysed data4. Another main set of decisions in any study design is the choice of the types of variables to be measured. 13

The observational design allows the scientist to gather and use background information concerning the principles being tested to predict better and understand the forthcoming outcome8. This method enables the researcher to either choose to perform independent research or look at similar experiments before making observations. Through this practice, it becomes possible for the experimenters to answer the question of what precisely the test is trying to explain. An experimental design also specifies the scientific method, outlining the type of materials used in the experiment in specific detail along with the exact procedures that will be taken10. The plans must be detailed and accurate so that another researcher can repeat the experiment and expect to get similar results. It is also necessary to list the methods used because it may be useful to go back to them after the test to explain some of the results that occurred. Lack of this has been noted in scientific research and has been attributed to the lack of proper research in this field. There is a need for the researchers to adopt a good research design which clearly outlines the methods used during the research process. Variables Variables refer to something that can change or vary14. A research design aims at looking for a link between two or more variables. Identification of variables in scientific research helps to determine how to analyse data and answer questions. In an analytic design, the researcher studies the associations between variables for outcome prediction and drawing inference concerning cause and effect. Considering the association between two variables, the first to occur is called the predictor variable, and the other is the outcome variable. Mostly, observational studies have a lot of predictor variables6. The credibility of research depends on having the right selection of variables as it can influence the research findings 4. The 14

purpose of all research experiments is to describe and explain variance in the world9. In an investigation, variables can either be dependent or, independent. Variables are not manipulated but are instead observed as they naturally occur. The associations between them are then studied. Dependent variable A dependent variable is one that depends on other factors. In an experiment, this variable is usually observed about the changes that happen to the other elements8. Independent variable On the other hand, an independent variable is one that stands alone and is not changed by the other variables being measured9, and this is the variable that is observed to see whether it causes a change in other variables; the dependent variable. Figure 1: Dependent and Independent Variables A dependent variable is a variable being tested in a scientific experiment8. The dependent variable is 'dependent' on the independent variable. As the experimenter changes the independent variable, the change in the dependent variable is observed and recorded. Controlled variable This variable is fixed and constant; it does not change within an experimental framework. The more variables that can be controlled and fixed, the more confidence you have in your results 15

being influenced by your independent variable. In scientific research, the choice of variables is very crucial to successful findings of the experiment8. Most of the forensic science research is not appropriately conducted due to the poor choice of the variables or not controlling variables, and this needs to be improved5. Samples Research investigation commences from a straightforward sampling of data. Nonetheless, sometimes there is no guarantee about the accuracy and representativeness of the data. The mere existence of data and the ability to acquire it does not necessarily imply data accuracy or suitability to represent and or reconstruct a contamination event10. The samples used in the research should be adequate and representative to have a trustworthy conclusion 2. The guidelines utilised in making samples comparisons in forensic disciplines lack thoroughly detailed structure, and this is due to the lack of a standardised method of making comparisons3. The samples contained in the research should reflect the relevant conditions and populations specific to the case adequately. Errors were occurring in the interpretation of research data, partly resulting from the use of minimal data samples to make comparisons and consequently leading to poor results4. The PCAST report 2016 discusses what should be expected in validation studies. PCAST indicated that statistical methods are well developed and have been validated for singlesource DNA evidence and latent print analysis. However, PCAST reported that additional studies are needed regarding the validity of forensic examinations in other forensic science disciplines such as bite marks, impression and evidence62. Assessing the reliability and validity of forensic investigations is a crucial step in developing sound science to measure the strength of evidence and statisticians can contribute to the design and analysis of such studies. 16

Data analysis Suitable statistical tests should be applied for the form of data obtained. The statistics that mainly clarify a research question first depend on the problem and secondly on the data4. There are different methods applied to the data, and this can be a) Visual analysis of data, b) classical statistics that include, specific interval, hypotheses, and others., and c) Bayesian statistics2. The statistics applied in the research should correspond to the research question, easy to understand, and able to produce results and this is significant in forensic science research because the data obtained for the analysis can be easily analysed. A conclusion can be made from the results5. Biased samples have been a source of errors in research. These are samples are those in which the method used to create the sample results in samples that are systematically different from the population. An incorrectly drawn sample can bias the conclusions from the start7. Overgeneralisation could also occur when the findings from one population might not apply to another population. All of these errors result from incorrect data analysis. It is, therefore, essential that a scientist uses a wide range of analytical tools. Additionally, a multidisciplinary approach is required in forensic research mainly because each discipline requires technical expertise while collecting and preparing evidence. Statistics in data analysis has a crucial role to play in helping to address the challenges of forensic science5. Controls Controls are used to minimise the effect of variables that are not the interest of the study 12. Through controls, scientists can ensure that there are no deviations in the experiment. Scientific research can either be positively or negatively controlled. The main difference 17

between positive and negative control is that positive control gives a response to the analysis, whereas negative control does not provide an answer. A positive control refers to a sample known to contain a particular substance, which would cause a positive result and verify that the test works12. This type of test always gives the result as a “yes.” It is a good indication to know if the test works. Hence, positive controls are used to evaluate the validity of an examination9. In forensic science research, test validity is fundamental in ensuring that the results obtained will be correct. Therefore scientists in this field need to ensure they have controls to guide the research process. If the positive control does not give the expected result, then a different method should be used. A negative control is a sample which is known not to contain a particular substance, but which would produce a negative result and verify that the test works 12. An essential aspect of collecting evidence is to properly obtain control samples taken from a known source against which the examiner can compare samples taken from the crime scene. The negative control is not exposed to the experimental test directly8. It is done parallel to the experiment as a control experiment. The negative control is used to confirm that there is no response to the reagent or the microorganism used in the test. To get a good result from the negative control, one should ensure that there is no net response to the test. Hence, negative controls help identify outside influences on the experiment. Discussion The review seeks to analyse recently published forensic papers to establish whether appropriate research methods were followed while undertaking the research. The review focuses on several papers from various fields of forensic science. The best practices of research, as discussed in the introduction, focuses on whether the forensic articles included 18

the proper research question, formulation of hypotheses, experimental design, variables used, sampling, data analysis, and controls. Examples are discussed. Fingerprints Carlos Magno & Alves Girelli48 conducted a study to investigate the identification of documents on the web using fingerprints. Their paper has a clearly defined research problem. The study begins with a piece of clear and detailed background information on the topic. The study, however, lacks a hypothesis. Hypothesis helps a researcher to predict a pos

The idea that most of the forensic publications lack adequate scientific foundation is a critical issue that needs to be addressed to improve the validity and reliability of conclusions made in forensic science research. The 2009 National Academy of Sciences report Strengthening Forensic Science in the United States: A Path

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