Forensic Practitioner\ s Guide to the Interpretation of Complex DNA Profiles

Over the past twenty years, there’s been a gradual shift in the way forensic scientists approach the evaluation of DNA profiling evidence that is taken to court. Many laboratories are now adopting ‘probabilistic genotyping’ to interpret complex DNA mixtures. However, current practice is very diverse, where a whole range of technologies are used to interpret DNA profiles and the software approaches advocated are commonly used throughout the world. Forensic Practitioner’s Guide to the Interpretation of Complex DNA Profiles places the main concepts of DNA profiling into context and fills a niche that is unoccupied in current literature. The book begins with an introduction to basic forensic genetics, covering a brief historical description of the development and harmonization of STR markers and national DNA databases. The laws of statistics are described, along with the likelihood ratio based on Hardy-Weinberg equilibrium and alternative models considering sub-structuring and relatedness. The historical development of low template mixture analysis, theory and practice, is also described, so the reader has a full understanding of rationale and progression. Evaluation of evidence and statement writing is described in detail, along with common pitfalls and their avoidance. The authors have been at the forefront of the revolution, having made substantial contributions to theory and practice over the past two decades. All methods described are open-source and freely available, supported by sets of test-data and links to web-sites with further information. This book is written primarily for the biologist with little or no statistical training. However, sufficient information will also be provided for the experienced statistician. Consequently, the book appeals to a diverse audience Covers short tandem repeat (STR) analysis, including database searching and massive parallel sequencing (both STRs and SNPs) Encourages dissemination and understanding of probabilistic...

Dr. Peter Gill joined the Forensic Science Service (FSS) in 1982. He began his research into DNA in 1985, collaborating with Sir Alec Jeffreys of Leicester University. In the same year they published the first demonstration of the forensic application of DNA profiling. In 1987, Dr. Gill was given an award under the civil service inventor’s scheme for discovery of the preferential sperm DNA extraction technique and the development of associated forensic tests. He was employed as Senior Principal Research Scientist at the Forensic Science Service (FSS). Currently, he hold concurrent positions at Oslo University Hospital and the University of Oslo where he is Professor of Forensic Genetics.

Romanovs
In 1993-4, Dr. Gill was responsible for leading the team which confirmed the identity of the remains of the Romanov family, murdered in 1918, and also the subsequent investigation which disproved the claim of Anna Anderson to be the Duchess Anastasia (using tissue preserved in a paraffin wax block for several decades). This was an early example of an historical mystery that was solved by the analysis of very degraded and aged material, and was one of the first demonstrations of low-template DNA analysis.

Low-template DNA
In relation to the above, Dr. Gill was responsible for developing a routine casework-based ‘super-sensitive’ method of DNA profiling that was capable of analysing DNA profiles from a handful of cells. This method was originally known as low-copy-number (LCN) DNA profiling. Now it is known as Low template DNA profiling. New statistical methods and thinking were also developed to facilitate the new methods.

National DNA database
Dr. Gill was responsible for leading the team that developed the first multiplex DNA systems to be used in a National DNA database anywhere in the world, and for the design of interpretation methods that are in current use (c.1995).
Court reporting: Dr. Gill has been involved with giving evidence in several high profile (controversial) cases – including the Doheny / Adams appeals, and the Omagh bombing trial in the UK.

Membership of scientific societies
Currently, Dr. Gill is a member of the European Network of Forensic Science Institutes and ex-chair of the ‘methods, analysis and interpretation sub-section’ He is chair of the International society for forensic genetics DNA commission on mixtures and has written a number of ISFG recommendations on low-template, mixture interpretation and evaluation of evidence that are highly cited. D. Gill is a member of the European DNA Profiling Group (EDNAP). He has published more than 200 papers in the international scientific literature which have been cited more than 20,000 times – many of these are collaborative papers under the auspices of ISFG, EDNAP and ENFSI. He is the recipient of the 2013 Scientific Prize of the International Society for Forensic Genetics.

Affiliations and Expertise
Forensic Genetics Research Group, Oslo University Hospital; Institute of Clinical Medicine, University of Oslo, Norwa

Øyvind Bleka has a background as a statistician and works as a researcher in the Department of Forensic Sciences at Oslo University Hospital, in Norway. He holds a PhD in Forensic Statistics from the University of Oslo where he developed EuroForMix. Later, he also developed the expert system software CaseSolver. Øyvind also works with development of age prediction models based on biological information such as radiological and epigenetics methods.

Oskar Hansson is head of the Reporting officers and research unit at the department of Forensic Sciences, Oslo University Hospital (OUS), Norway. He started his career at the national forensic laboratory (NFC) in Sweden in 2002. In 2008 he was recruited to Norway to work with the implementation of a new workflow for reference sample analysis. Between 2017 and 2019 he was research group leader for the Forensic Genetics Research Group at OUS. He has 18 years’ experience in forensic genetics, working primarily with laboratory development, automation, public procurement, validation and implementation of new methods. His background is in molecular biology and programming and a PhD degree in forensic genetics. He has provided training in various international mixture interpretation and validation workshops. Oskar has developed and maintains the STR-validator R package, which averaged in excess of 500 monthly installs during 2019.

Corina Benschop is a post-doctoral researcher / research scientist within the research team of the biological traces division at the Netherlands Forensic Institute. Her focus is on interpretation of complex DNA profiles (guidelines and tools, insight in the trends, risks and limitations about likelihood ratio computations, inter- and intra-laboratory studies and training through workshops worldwide).

Hinda Haned became a professor at the University of Amsterdam in 2018, where she researches and develops solutions for best practices for safe and responsible applications of machine learning. Haned is also lead data scientist at Ahold Delhaize since 2015 and principal scientist since 2018. Her activities at Ahold Delhaize involve designing and building solutions to answer business questions with data mining and machine learning techniques. From 2010 to 2015, she worked as a research statistician at the Netherlands Forensic Institute (NFI). During her time at NFI, she developed statistical models and open source software to facilitate the interpretation of complex DNA profiles. Haned has published extensively in multiple international peer-reviewed journals in forensic science. In 2014, she was awarded an EU grant to develop open source forensic software and organize educational workshops on the statistical evaluation of forensic DNA evidence. Haned obtained her PhD in Applied Statistics from the University of Lyon, France, in 2010.