Analysing and exemplifying forensic conclusion criteria in terms of Bayesian decision theory

There is ongoing discussion in forensic science and the law about the nature of the conclusions reached based on scientific evidence, and on how such conclusions – and conclusion criteria – may be justified by rational argument. Examples, among others, are encountered in fields such as fingermarks (e.g., ‘this fingermark comes from Mr. A's left thumb’), handwriting examinations (e.g., ‘the questioned signature is that of Mr. A’), kinship analyses (e.g., ‘Mr. A is the father of child C’) or anthropology (e.g., ‘these are human remains'). Considerable developments using formal methods of reasoning based on, for example (Bayesian) decision theory, are available in literature, but currently such reference principles are not explicitly used in operational forensic reporting and ensuing decision-making. Moreover, applied examples, illustrating the principles, are scarce. A potential consequence of this in practical proceedings, and hence a cause of concern, is that underlying ingredients of decision criteria (such as losses quantifying the undesirability of adverse decision consequences), are not properly dealt with. There is merit, thus, in pursuing the study and discussion of practical examples, demonstrating that formal decision-theoretic principles are not merely conceptual considerations. Actually, these principles can be shown to underpin practical decision-making procedures and existing legal decision criteria, though often not explicitly apparent as such. In this paper, we will present such examples and discuss their properties from a Bayesian decision-theoretic perspective. We will argue that these are essential concepts for an informed discourse on decision-making across forensic disciplines and the development of a coherent view on this topic. We will also emphasize that these principles are of normative nature in the sense that they provide standards against which actual judgment and decision-making may be compared. Most importantly, these standards are justified independently of peoples' observable decision behaviour, and of whether or not one endorses these formal methods of reasoning.     

Knowing receipt: continuing trusts and conscionability Byers v Saudi National Bank

In Byers v Saudi National Bank [2022] EWCA Civ 43 the Court of Appeal examined a seemingly straightforward question: where rights are dissipated in breach of trust, is it a necessary condition of the recipient being liable for ‘knowing receipt’ that the dissipation did not extinguish the beneficiary's rights? The answer sheds considerable light on the juridical nature of liability for ‘knowing receipt’. This note argues that the Court of Appeal's analysis correctly supports the theory that so-called ‘recipient’ liability is in fact a species of liability for breach of trust. It also examines the implications of that conclusion for the elements of, and remedies for, ‘knowing receipt’.     

事实认定的概率分析

根据概率分析所涉及证据数量的不同,事实认定概率分析可分为单一证据维度和证据组合维度。在单一证据维度中,司法鉴定领域会不断涌现像DNA证据那样兼具实证统计数据和高度科学确认度的统计概率证据。在证据组合维度中,事实认定不可能通过数学推理实现,其原因主要有：事实认定过程复杂,数学推理难以模拟;数学推理并非司法证明思维的＂母语＂,而是一门需要翻译的＂外语＂;数学推理会通过＂量＂上的运算模糊、混淆乃至掩盖了＂质＂上的差别。     

The different types of reports produced in digital forensic investigations

The importance of ensuring the results of any digital forensic (DF) examination are effectively communicated cannot be understated. In most cases, this communication will be done via written report, yet despite this there is arguably limited best practice guidance available which is specific for this field in regards to report construction. Poor reporting practices in DF are likely to undermine the reliability of evidence provided across this field, where there is a need for formalised guidance regarding the requirements for effective DF report construction; this should not be a task left solely to each individual practitioner to determine without instruction. For this, the field of DF should look to the wider forensic community and the existing work in this area for support. In line with many other ‘traditional’ forensic science types, a DF practitioner can be commissioned to report in one of three ways - ‘technical’, ‘investigative’ or ‘evaluative’, where each reporting type maintains a specific purpose and interpretative-context, determined by the examination workflow undertaken by a practitioner following client instruction. This work draws upon guidance set out in fundamental forensic science reporting literature in order to describe each reporting type in turn, outlining their scope, content and construction requirements in an attempt to provide support for the DF field.     

Private prosecution in Singapore: understanding locus standi and measures in place to minimise abuse

In Singapore, as is the case with other commonwealth countries, the general rule is that once any offence has been committed, it is for the state to prosecute the alleged offender. This explains why Article 35(8) of the Constitution provides that ‘[t]he Attorney-General shall have power, exercisable at his discretion, to institute, conduct or discontinue any proceedings for any offence’. Article 35(8) is reinforced by section 11 of the Criminal Procedure Code, which provides that ‘[t]he Attorney-General shall be the Public Prosecutor and shall have the control and direction of criminal prosecutions and proceedings under this Code or any other written law’. However, as is the case with other commonwealth countries, the public prosecutor in Singapore does not have an exclusive right to prosecute. In some circumstances other government agencies or private individuals may institute and have instituted prosecutions. The purpose of this article is to discuss the issues of locus standi to institute a private prosecution and the measures in place in Singapore to minimise abusing the right to institute a private prosecution. In discussing these issues, the author, where necessary, compares the Singapore position with that of other commonwealth jurisdictions and makes recommendations on how legislation could be amended in Singapore to address some of the challenges.     

Complex mixtures: A critical examination of a paper by Homer et al.

DNA evidence in criminal cases may be challenging to interpret if several individuals have contributed to a DNA-mixture. The genetic markers conventionally used for forensic applications may be insufficient to resolve cases where there is a small fraction of DNA (say less than 10%) from some contributors or where there are several (say more than 4) contributors. Recently methods have been proposed that claim to substantially improve on existing approaches [1]. The basic idea is to use high-density single nucleotide polymorphism (SNP) genotyping arrays including as many as 500,000 markers or more and explicitly exploit raw allele intensity measures. It is claimed that trace fractions of less than 0.1% can be reliably detected in mixtures with a large number of contributors. Specific forensic issues pertaining to the amount and quality of DNA are not discussed in the paper and will not be addressed here. Rather our paper critically examines the statistical methods and the validity of the conclusions drawn in Homer et al. (2008) [1].We provide a mathematical argument showing that the suggested statistical approach will give misleading results for important cases. For instance, for a two person mixture an individual contributing less than 33% is expected to be declared a non-contributor. The quoted threshold 33% applies when all relative allele frequencies are 0.5. Simulations confirmed the mathematical findings and also provide results for more complex cases. We specified several scenarios for the number of contributors, the mixing proportions and allele frequencies and simulated as many as 500,000 SNPs.A controlled, blinded experiment was performed using the Illumina GoldenGate^® 360 SNP test panel. Twenty-five mixtures were created from 2 to 5 contributors with proportions ranging from 0.01 to 0.99. The findings were consistent with the mathematical result and the simulations.We conclude that it is not possible to reliably infer the presence of minor contributors to mixtures following the approach suggested in Homer et al. (2008) [1]. The basic problem is that the method fails to account for mixing proportions.     

统计学方法在微量物证数据处理中的应用

统计学方法在微量物证理化检验工作中受到越来越多的重视,采用有效的统计学方法对检验数据进行分析,不仅能够深度挖掘复杂数据背后信息,还能不断提高数据的应用价值和证据本身的证据价值。本文对目前微量物证领域常用统计学方法进行归纳总结,简要介绍了常用统计方法的应用,对各类方法优缺点进行说明。最后,对法庭科学工作者都比较感兴趣的贝叶斯统计与似然比方法在理化检验数据统计分析中的应用进行了介绍。     

“This case is about you and your future”: Towards Judgments for Children

A handful of ‘child-friendly’ judgments have emerged in the UK in recent years, attempting to adopt a child-centred approach to the decision-making stage of the legal process. Most notable is Sir Peter Jackson's judgment in Re A: Letter to a Young Person which, in taking the form of a letter to the child, has been applauded as a model of how to achieve ‘child friendly justice’. This article examines how and why the form and presentation of judicial decisions is an important aspect of children's access to justice, considering not just the potential but the duty of judges to enhance children's status and capacities as legal citizens through judgment writing. We identify four potential functions of judgments written for children (communicative, developmental, instructive and legally transformative), and call for a radical reappraisal of the way in which judgments are constructed and conveyed with a view to promoting children's access to justice.     

A step towards improving workflow practices for volume crime investigations: outcomes of a 90-day trial in South Australia

The provision of forensic science services in volume crime investigations works most successfully as a partnership between police agencies and external forensic laboratories as opposed to a client/provider model where unlimited demand ignores finite resources. The principles of Lean Six Sigma have been applied in various laboratories to improve workflow through identification of wasteful work practices. These strategies are aimed at process optimisation through the application of triaging, a concept that has rarely been studied yet referenced strongly in the literature. The South Australia End to End 90-Day Trial: facilitating quicker justice through timely evidence processing, is a collaborative approach between South Australia Police and Forensic Science South Australia. This trial applied evidence-based policing principles, a law enforcement philosophy that uses research undertaken with scientific processes to inform law-enforcement decision-making. The results demonstrate how a review of processes and the removal of non-value adding activities can improve service delivery while not exhausting those ‘finite resources’.     

A re‐analysis that supports our main results: A reply to Levine et al.

Levine et al. (2018) criticized our meta‐analysis, but their conclusion was the same as ours: The cognitive approach to lie detection results in a modest improvement. We address and dismiss Levine et al.'s (2018) three criticisms. Regarding the ‘confound’, in our meta‐analysis we averaged the results of two cells on statistical grounds, which does not constitute a confound in statistical terms. Regarding ‘aberrant controls’, that depends entirely on the benchmarks selected and type of statistical test and meta‐analysis used. Regarding ‘unreliable data’, the claim that there is a positive relationship between ‘unreliable’ data and total accuracy in the cognitive lie detection conditions is not even supported by their own data (p = .16). We conclude with a request to Levine et al. to focus on our shared aim: to develop interview protocols that enable lie detection.     

法证披露模型:应当向法证专家披露什么和法证专家应当披露什么?

法律上的披露问题主要集中在检控方向辩护方提供或者隐瞒了哪些证据。在本文中,我们将披露的概念扩展到更广泛的情境下,在这种情境下,披露失误可能导致误判。我们引入了一个概念模型,即“法证信息披露”,它涉及哪些信息应该披露给法证检验人员,以及法证检验人员应当披露哪些信息。本文全面概述了四类利益相关者的动态交互:法证服务、调查、法律和外部利益相关者。我们通过五个问题讨论了法证信息披露模式的有效实施,即如果要向法证检验人员或者由法证检验人员提供最好的信息,以提高法证决策质素,并尽量减少偏差,则什么时候进行披露?披露什么?如何披露?向谁披露?为什么披露?     

法医骨学推断计算机专家系统的开发研究

目的构建计算机法医骨学推断专家系统。方法利用面向对象的方法,综合现有法医人类学统计资料,系统结合了模糊匹配和DS证据理论两种推理手段,使用融合了框架和产生式的知识表示方法进行专家系统构建。结果开发出具有开放知识库、可操作性强的法医骨学性别、年龄、身高推断软件。结论本系统具有较大的可信度和有效性,能够很好的辅助法医技术人员开展工作。     

Privacy and Search Engines: Forgetting or Contextualizing?

This article considers the much‐criticized ‘right to be forgotten’ in the context of the European Court of Justice's judgment in the Google Spain case. It defends the ‘right to be forgotten’ as a metaphor that can provide us with a better understanding of the particular privacy concerns of the search‐engine age and their interaction with the freedom to access information, and draws on Goffman's idea of ‘information games’ and Nissenbaum's theory of ‘contextual integrity’. While supporting the principles that underpin the judgment, the article rejects the Court's binary approach of ‘forgetting’ versus ‘remembering’ personal information. Instead, it argues that the EU legislator should introduce more nuanced means of addressing modern privacy concerns. By establishing two remedies – ‘delisting’ or ‘reordering’, depending on the nature of the information – online information flows can be adjusted to preserve both the right to privacy and the freedom to access information in more contextually appropriate ways.     

The likelihood approach to compare populations: a study on DNA evidence and pitfalls of intuitions

The paper follows on from earlier work [Taroni F and Aitken CGG. Probabilistic reasoning in the law, Part 1: assessment of probabilities and explanation of the value of DNA evidence. Science & Justice 1998; 38: 165-177]. Different explanations of the value of DNA evidence were presented to students from two schools of forensic science and to members of fifteen laboratories all around the world. The responses were divided into two groups; those which came from a school or laboratory identified as Bayesian and those which came from a school or laboratory identified as non-Bayesian. The paper analyses these responses using a likelihood approach. This approach is more consistent with a Bayesian analysis than one based on a frequentist approach, as was reported by Taroni F and Aitken CGG. [Probabilistic reasoning in the law, Part 1: assessment of probabilities and explanation of the value of DNA evidence] in Science & Justice 1998.     

Evaluation of Stature Estimation from the Database for Forensic Anthropology*†

Abstract: Trotter and Gleser’s ( 1 - 3 ) stature equations, conventionally used to estimate stature, are not appropriate to use in the modern forensic context. In this study, stature is assessed with a modern (birth years after 1944) American sample (N = 242) derived from the National Institute of Justice Database for Forensic Anthropology in the United States and the Forensic Anthropology Databank. New stature formulae have been calculated using forensic stature (FSTAT) and a combined dataset of forensic, cadaver, and measured statures referred to as Any Stature (ASTAT). The new FSTAT‐based equations had an improved accuracy in Blacks with little improvement over Ousley’s ( 4 ) equations for Whites. ASTAT‐based equations performed equal to those of FSTAT equations and may be more appropriate, because they reflect both the variation in reported statures and in cadaver statures. It is essential to use not only equations based on forensic statures, but also equations based on modern samples.     

Reflective Judgement and Prudential Rationality: A Contribution to an Inclusive Practical Application of Law

Hannah Arendt has developed a theory of the importance of judgment of taste for political manners, founded on the Kantian aesthetic theory. Nowadays this theory is considered a current theoretical reference for establishing a political way to reconcile the demands of the radicalization of deliberative democracy with the need for political inclusion (Iris Marion Young, Seyla Benhabib). Albena Azmanova in her The Scandal of Reason: A Critical Theory of Political Judgment proposes an inclusive political rhetoric. The political theory founded on judgment is based on Kant’s philosophy; it was developed by Arendt and has greatly influenced the current debate, as an alternative theory in which the moral basis of law can be more sensitive to human contexts; a universalist theory more adequate for dealing with the tragic dimension of human life. The theory of political judgment uses the concepts of reflective judgment and ‘enlarged thought’ as its main concepts. As a starting point, a theory like this considers the singular judgments of justice that each person makes. The background, therefore, is not a rational foundation of principles, but the capacity of rational beings to make judgments. This post-metaphysical theory of law, based on a theory of judgment, is a critique of legal positivism, but presents itself as an alternative to the idealistic theory of law. But this theoretical project has received some criticism related to the adequacy of Arendt’s rereading of Kantian philosophy and her attempt to approximate Kant’s reflective judgment to the Aristotelian concept of phronêsis. Some critics, such as Bryan Garsten, believe that Kant’s rhetoric of public reason diminished and displaced the prudential faculty of judgment that Arendt is to be interested in reviving. Arendt’s attempt to find a theory of judgment in Kant’s aesthetic theory is not successful, in Garsten’s view. Our purpose is to show that a critical theory of judicial judgment is not only possible, but necessary; Arendt’s theory of judgment offers an important contribution to a critical theory of judicial judgment, particularly one devoted to the construction of a legal theory that prioritizes a politics of social inclusion. This theory proposes a critical approach to the project of the procedural conception of democracy, since it can mask social exclusion. An adequate understanding of judicial argumentation cannot forget that it happens in a rhetorical context: it is not only important what a discourse says, but how it says it. The radicalization of deliberative democracy supposes a revision of the ways judicial deliberation is thought: not by reference to universal or at least general principles, but taking into consideration what is ‘critically relevant’, with a view to remedying social injustice (following Azmanova).

     

The Value of ‘Integration’ in European Law—The Implications of the Förster Case on Legal Assessment of Integration Conditions for Third‐Country Nationals

The European Court of Justice's Förster judgment can lead to a reduction of legal uncertainty caused by integration requirements for third‐country nationals. The judgment has created a strong ‘assumption of integration’ after five years of legal residence because it equalised integration requirements for European students to access the welfare system of host Member States with a requirement of five years legal residence. Almost all pieces of European legal migration law also contain five‐year residence requirements after which the status of third‐country nationals improves. However, these improvements are mostly subjected to the fulfilment of additional integration requirements. To keep coherence with European law, courts will not be able to disregard the Förster‘assumption of integration’ when assessing the legality of integration conditions for third‐country nationals put in place in addition to residence requirements.     

Black Spiders Weaving Webs: The Constitutional Implications of Executive Veto of Tribunal Determinations

In R (Evans) v Attorney General, the Supreme Court quashed the Attorney General's statutory veto of the Upper Tribunal's original determination made under freedom of information legislation. The Upper Tribunal had held that so‐called ‘advocacy’ memos should be published after a full hearing on the merits. The Supreme Court split five to two, with the lead judgment of Lord Neuberger using constitutional rather than administrative language and focusing on the rule of law. This note raises four objections to the lead judgment. First, it argues that the Upper Tribunal was acting in an executive not judicial capacity and the veto was not therefore a breach of the rule of law. Secondly it suggests the veto clause is best understood as a variant Henry VIII clause. Thirdly, it suggests Lord Neuberger's judgment is founded on a paradox. Finally, it argues that the judgment undermines parliamentary sovereignty. Future implications are then considered.     

The Embedded Epistemologist: Dispatches from the Legal Front*

In ordinary circumstances, we can assess the worth of evidence well enough without benefit of any theory; but when evidence is especially complex, ambiguous, or emotionally disturbing—as it often is in legal contexts—epistemological theory may be helpful. A legal fact‐finder is asked to determine whether the proposition that the defendant is guilty, or is liable, is established to the required degree of proof by the [admissible] evidence presented; i.e., to make an epistemological appraisal. The foundherentist theory developed in Evidence and Inquiry can help us understand what this means; and reveals that degrees of proof cannot be construed as mathematical probabilities: a point illustrated by comparing the advantages of a foundherentist analysis with the disadvantages of probabilistic analyses of the evidence in the Sacco and Vanzetti case (1921), and of the role of the statistical evidence in Collins (1968).