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Legal work


I undertake work as an expert witness in probability and statistics in forensics and legal arguments. I completed expert witness training with Bond Solon under the auspices of Cardiff University Law Dept (2007-2008).

I have been an expert witness or consultant in multiple major ciminal and civil cases. I have also delivered training and seminars on the role of Bayes and probability analysis to legal professionals around the world, including the Judges and Staff of the International Criminal Court of The Hague.

Since June 2011 I have led an international consortium (Bayes and the Law) of statisticians, lawyers and forensic scientists working to improve the use of statistics in court. In 2016 I led the 6-month Programme on Probability and Statistics in Forensic Science at the Isaac Newton Institute for Mathematical Sciences, University of Cambridge, where I was also a Simons Fellow.

Key relevant papers, casework examples, seminars and videos are listed below.


Key legal papers

  • Fenton, N. E., & Lagnado, D. A. (2021). Bayesianism: Objections and Rebuttals. In Christian Dahlman, A. Stein, & G. Tuzet (Eds.), Philosophical Foundations of Evidence Law.

  • Fenton, N.E. , Jamieson, A., Gomes, S., & Neil, M. (2020). "On the limitations of probabilistic claims about the probative value of mixed DNA profile evidence".

  • Fenton, N. E., Lagnado, D. A., Dahlman, C., & Neil, M. (2019). "The Opportunity Prior: A proof-based prior for criminal cases", Vol 18(4), 237-253 Law, Probability and Risk, DOI 10.1093/lpr/mgz007. Full paper from OUP.

  • Balding, D., Fenton, N. E., Gill, R., Lagnado, D. & Schneps, L. "Twelve Guiding Principles and Recommendations for Dealing with Quantitative Evidence in Criminal Law". (2017). Isaac Newton Institute Report INI 16061,

  • Fenton N.E, Neil M, Berger D, “Bayes and the Law”, Annual Review of Statistics and Its Application, Volume 3, 2016 (June), pp 51-77 .Pre-publication version here and here is the Supplementary Material See also blog posting

  • Fenton, N. E., D. Berger, D. Lagnado,  M. Neil and A. Hsu, (2014). "When ‘neutral’ evidence still has probative value (with implications from the Barry George Case)",  Science and Justice, 54(4), 274-287  (pre-publication draft here)

  • Fenton, N. E. (2011). "Science and law: Improve statistics in court." Nature 479: 36-37.  Paper on Nature online website is here.  An extended draft on which this was based is here

  • Fenton, N.E. and Neil, M. (2011), 'Avoiding Legal Fallacies in Practice Using Bayesian Networks', Australian Journal of Legal Philosophy 36, 114-151, 2011 ISSN 1440-4982 (extended preprint draft here).

  • Fenton, N. and Neil, M. (2010). "Comparing risks of alternative medical diagnosis using Bayesian arguments." Journal of Biomedical Informatics, 43: 485-495,  Preprint here.



Case work examples

  • Testimony to the Corona Investigative Committee (Germany): "How flawed data shaped the covid crisis and its response to it", 12 May 2023. Full testimony (presented 12 May 2023) is here (my testimony starts at 2:29:28):

  • Expert witness (Jakarta, Indonesia) in the case contesting mandates brought against the President & Health Minister of Indonesia. Focuses on the statistical evidence relating to covid risk and the efficacy/safety of vaccines. Video of testimony in court.

  • Affidavit in the Provincial Court of New Brunswick in the case between HM The Queen v  Hutchings and Butler, Court File Numbers: 09677102, 09678002, 09722802 and 09677002. Feb 2022. Focuses on the statistical evidence relating to covid risk and the efficacy/safety of vaccines

  • Expert advisor on statistical analysis of mixed profile DNA evidence in the case of R v DC and others in the Crown Court Peterborough, Jan 2021

  • Affidavit in the High Court of New Zealand Wellington Registry, CIV-2021-485-000595 in support of Application for Judicial Review of the making and amendment of the COVID-19 Public Health Response (Vaccinations) Order 2021 under section 11 of the COVID-19, Public Health Response Act 2020. Dec 2020

  • Nebraska Attorney General's October 14, 2021 legal opinion on prescribing Ivermectin cites our Bayesian analysis (page 16 & footnotes 101 and 104). Rules that it can be prescribed with informed consent

  • Expert adviser on probabilistic analysis of gunshot residue evidence in the case of R v RLC Case No: T20197339, Luton Crown Court, 2020

  • April 2019-Dec 2019: Expert consultant to Defence in (San Diego murder) case of Florencio Jose Dominguez  that challenged the use of new statistical analyses for a mixed DNA profile. The case was settled Dec 2019 when Dominguez (who was sentenced to 50 years to life for the 2008 murder) was released after pleading guilty to a reduced charge

  • Nov 2018: Expert consultant to Mondex Corporation Canada in the case of the Lewenstein family claims to ownership of the Kandinsky painting ‘Bilt mit Hausern’ currently housed at the Stedelijk Museum in Amsterdam. My report used Bayesian networks to determine probability of ownership

  • Major contributor The Turing Institute submission to the House of Lords Science and Technology Committee inquiry into Forensic Science. Published on the Parliament website. Oct 2018

  • Expert witness in trial of R v APR et al on statistical analysis of drugs on banknotes, Liverpool Crown Court, Nov 2016

  • Expert witness in trial of R V MR on statistical analysis of drugs on banknotes, Snaresbrook Crown Court, May-August 2016

  • Expert advisor for the case of Ben Geen (see Guardian article here). Archived version is here.

  • Member of Advisory Group of the Forensic Science Special Interest Group (FoSci SIG) since Feb 2013

  • Expert adviser in the retrial of R v Gary Dobson and David Norris (the Stephen Lawrence case) 2011-21012. I advised on probabilistic issues relating to the DNA evidence. 

  • Expert adviser in the Appeal case of R v K (2012) Appeal. This was a youth convicted of involvement in the Croydon riots of the summer of 2012. I advised on probablistic issues.   

  • Expert adviser in an ongoing case (R v LW) – and potentially the most significant ever for Bayes and DNA – where I was asked to review the DNA evidence.

  • One of 15 UK academics invited to contribute to Home Office workshop on “Forecasting rare and extreme criminal events”, 12 June 2009. Following the workshop I prepared a report recommending a strategy for piloting the use Bayesian networks to support the Government's anti-terrorism PREVENT Programme. My recommendations were subsequently incorporated into the Programme.

  • Expert witness (in Bayesian analysis/decision-making) for the claimant on a medical negligence case against the NHS.  (July-August 2008)

  • Expert witness on probabilistic risk analysis in the case of R vs Levi Bellfield at the Old Bailey (July 2007 – Feb 2008). My first report focused on the uncertainty relating to the vehicle identification in the case of the Marsha McDonnell murder. My second report highlighted a number of fallacies in the Prosecution Opening and was used as the basis for the Defence case. 

  • Jan-Aug 2006:  Expert witness (on software quality and risk assessment) on a major legal case involving safety critical software in the rail industry.  The case was settled shortly before coming to court and my expert report (of some 200 pages) was crucial in securing a favourable settlement for the party that had engaged me.

Legal seminars

  • Annual Invited lecture "Bayesian Networks and the Law", University College London, MSc Course Crime and Forensic Science (since 2013)

  • Invited Seminar: "Statistical Issues with Probabilistic Genotyping", US National Forensic College, New York, 12 August 2021

  • Invited seminar: "Bayesianism: Objections and Rebuttals", On-line seminars on Philosophical Foundations of Evidence Law, under the auspices of the Departments of Law at Lund University, Sweden and Groningen University, The Netherlands,  11 May 2021

  • Invited talk: "On the limitations of probabilistic claims about the probative value of mixed DNA profile evidence", 6th Annual Questioning Forensics Conference, The Legal Aid Society, New York, USA, 29 Jan 2021

  • Respondent to seminar devoted to discussion of our paper "The Opportunity Prior: A Simple and Practical Solution to the Prior Probability Problem for Legal Cases", Philosophy of Science and Epistemology (LoPSE) Seminar Series, at the University of Gdansk, Poland, 13 Dec 2019

  • Invited Lecture "Resolving the so-called probabilistic paradoxes in legal reasoning with Bayesian networks",   International Workshop on BAYES AND INFERENCE TO THE BEST EXPLANATION IN CRIMINAL LAW, Groningen 8 Nov 2019.

  • Invited lecture to MSc students and Degree apprentices, Queen Mary: “Bayes and the Law: How much can we trust DNA evidence?”, 31 Oct 2019

  • Invited Talk "On the Role of Statistics in Miscarriages of Justice".  Meeting of the All-Party Parliamentary Group on Miscarriages of Justice. House of Commons, London 25 June 2018.

  • Invited keynote "Is there a Role for Bayes in the Law?",  Colloquium on Evidence Theory, Faculty of Law, Lund University, 26 April 2018

  • Invited Conference Presentation, "The benefits and pitfalls of Bayes in forensic analysis", 10th International Conference of the ERCM WG on  Computational and Methodological Statistics (CM Statistics 2017), Senate House, University of London 18 Dec 2017

  • Invited Lecture to Judges and Staff of the International Criminal Court, "The Power and Pitfalls of Probabilistic Evidence", International Criminal Court of The Hague, The Hague, Netherlands 4 July 2017. Slide show

  • Invited Talk: "Innocent until proven guilty: a fair approach to agreed prior probabilities",  JURIX 2016, 15 December 2016, Nice, France.

  • Invited Talk: "Recommendations and Guidelines for using Probability and Statistics in the Law",  Turing Gateway to Mathematics  - Dissemination Workshop on Probability and Statistics in Forensic Science, 1 Dec 2016, Cambridge

  • Opening talk: "Beyond a reasonable doubt: a Bayesian perspective", Workshop "Beyond a Reasonable Doubt : Scenarios and Bayesian Networks for Analyzing Forensic Evidence", Groningen, The Netherlands, 27 October 2016

  • Keynote talk: “Bayesian networks: challenges and opportunities in the law”, Workshop on Bayesian Networks and Argumentation in Evidence, Isaac Newton Institute for Mathematical Sciences, Cambridge. 27 September 2016, Video:

  • Keynote talk: "The Challenges of  Bayes in the Law", Workshop on "The nature of questions arising in court that can be addressed by probability and statistical methods", 30 August-2 September 2016, Isaac Newton Institute for Mathematical Sciences, Cambridge. Video:

  • Seminar: "Bayesian Networks and the Law", Isaac Newton Institute for Mathematical Sciences, Cambridge 24 August 2016

  • Invited Talk: "On the benefits and pitfalls of using the likelihood ratio to help understand the impact of forensic evidence", The Forensic Institute FORREST 2016,  Glasgow  5 July 2016. Slide Show

  • Invited Talk: "The prosecutor's fallacy and other errors of legal reasoning",  Investigation and Prosecution of Homicide Conference, Hilton Green Park Hotel, London 24 March 2016

  • Invited keynote: "Impediments and Opportunities to using Statistics and Probability in Legal Arguments",  Turing Gateway to Mathematics and Isaac Newton Institute for Mathematical Sciences Seminar on Probability and Statistics - Perspectives from the Legal Profession, The City Law School,  London, 9 Feb 2016. Slides here.

  • Invited Address "Beyond Likelihood Ratios",15th International Conference on Artificial Intelligence & Law  (ICAIL 2015), San Diego, June 12, 2015 

  • Accepted presentation: "Limitations and opportunities of the likelihood ratio approach for evidence evaluation", ICFIS (9th International Conference on Forensic Inference and Statistics), 19-22 August 2014, Leiden. Powerpoint slides here. Abstract here.

  • Plenary Address: "Improving Probability and Risk Assessment in the Law", Winchester Conference on Trust, Risk, Information and the Law, University of Winchester , 29 April 2014. Slides here.

  • Invited Lecture "Probability and the Law", Exeter University, 10 October 2013 (also part of the Exeter Initiative for Statistics and its Applications and the Royal Statistical Society). A  recording (with slides) of the lecture is here.

  • Invited Keynote  "Improving Legal Reasoning with Bayesian Networks", The Sixth European Workshop on Probabilistic Graphical Models (PGM2012), 19-21 Sept 2012, Granada, Spain

  • Invited Seminar "Bayes and the Law", University College London Centre for the Forensic Sciences, 21 March 2012

  • Invited presentation "Statistics and Bayesian reasoning ",  Crown Prosecution Service, Forensic Science Awareness Training, 9 March 2012

  • Invited presentation, "Potential for Bayesian reasoning in Digital Forensics", Digital Forensics Specialist Group , Home Office, 1 Feb 2012 

  • Invited presentation, "Bayes and the Law", Royal Statistical Society  London (Working Group on Statistics and the Law), 28 September 2011

  • Invited Presentation, "Improving the presention of legal evidence using Bayesian Networks", International Centre for Criminological Comparative Research (ICCCR) Annual Conference, 7-8 July 2011, The Open University.

  • Invited Seminar, "Uncertainty, Risk and Decision Making", LDJM (London Judgement and Decision Making Society),  University College London, 28 April 2010

  • Invited Seminar, "Uncertainty, Risk and Decision Making", Sheffield University, 18 March 2010

  • Accepted Paper: "Avoiding Legal Fallacies in Practice Using Bayesian Networks",  Seventh International Conference on Forensic Inference and Statistics. 2008: Lausanne, Switzerland, 21-23 August 2008.

  • Invited Keynote: "The prosecution fallacy and other probabilistic fallacies occuring in trials", Society of Expert Witnesses Conference, Swindon, 16 May 2008

  • Invited seminar: "Bayes on Trial", City University Business School, Faculty of Actuarial Science and Insurance, 6 Feb 2008


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