This article provides an explanation of the duties and responsibilities owed by forensic practitioners (and other expert witnesses) when preparing for and presenting evidence in criminal proceedings. It is written in the shadow of reports by the National Academy of Sciences (US), the National Institute of Standards and Technology (US), the Scottish Fingerprint Inquiry and a recent publication entitled ‘How to cross-examine forensic scientists: A guide for Lawyers’. The article examines potential responses to questions focused on the need for scientific research, validation, uncertainties, limitations and error, contextual bias and the way expert opinions are expressed in reports and oral testimony. Responses and the discussion is developed around thematics such as disclosure, transparency, epistemic modesty and impartiality derived from modern admissibility and procedure rules, codes of conduct, ethical and professional responsibilities and employment contracts. The article explains why forensic practitioners must respond to the rules and expectations of adversarial legal institutions. Simultaneously, in line with accusatorial principles, it suggests that forensic practitioners employed by the state ought to conduct themselves as model forensic scientists.

This article offers a critical overview of expert identification evidence based on images. It reviews the Australian case law and then, in an interdisciplinary manner, endeavours to explain methodological, technical and theoretical problems with facial mapping evidence. It suggests that extant admissibility jurisprudence and traditional safeguards associated with expert opinion evidence and the adversarial trial might not adequately protect those accused of committing criminal acts when they are confronted with incriminating expert identification evidence.

What happens to a country under constant surveillance? The recent decision in Atkins v The Queen provides a partial answer.1 The sheer availability of images seems to be driving decisions about their admissibility and use as identification evidence. Confronted with CCTV recordings associated with criminal activities English courts have been reluctant to restrict their admission or impose limitations on the scope or form of incriminating opinion derived from them. Although the Court of Appeal decision in Atkins v The Queen is concerned primarily with the way in which an opinion derived from CCTV images was expressed, the decision exposes jurisprudential weakness and continuing problems with photo comparison and facial-mapping evidence.

Purpose: Passport photographs are routinely incorporated onto official travel documentation to ascertain an individual’s identity. In Australia, passport photographs may be provided by a range of retail suppliers and photographed to a set of standards developed by the Department of Foreign Affairs and Trade. Whether these standards can provide consistency between craniofacial representation and other parameters throughout individual subjects is unknown. The paper aims to discuss this issue. Design/methodology/approach: This study tests the consistency of passport images with regard to parameters that are likely to affect suitability for use as passport documents. These parameters include, space and dimensionality, craniofacial representation, image sharpness, exposure and colour rendition. Findings: The examination found there was a significant degree of variation among the test results despite being completed using the same instructional guidelines designed to produce uniformity. Originality/value: The paper identifies a significant degree of variation among test results and suggests further review.

This article is a resource for lawyers approaching the cross-examination of forensic scientists (and other expert witnesses). Through a series of examples, it provides information that will assist lawyers to explore the probative value of forensic science evidence, in particular forensic comparison evidence, on the voir dire and at trial. Questions covering a broad range of potential topics and issues, including relevance, the expression of results, codes of conduct, limitations and errors, are supplemented with detailed commentary and references to authoritative reports and research on the validity and reliability of forensic science techniques.