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Forensic Data Science Laboratory & Forensic Speech Science Laboratory

What we do

LR-1D-GaussianThe Forensic Data Science Laboratory conducts research and development aimed at improving casework capabilities within and across multiple branches of forensic science, particularly casework conducted within the new paradigm for the evaluation of forensic evidence, i.e.:

  • quantification of strength of evidence as a likelihood ratio

  • calculation of likelihood ratios using relevant data, quantitative measurement, and statistical models

  • validation of system performance under conditions reflecting those of the case under investigation

  • reduction of the potential for cognitive bias

The likelihood-ratio framework is the logically correct framework for evaluation of forensic evidence. The potential for cognitive bias can be reduced by restricting subjective judgements to matters such as selection of appropriate data to enter into the system and by directly reporting the output of the statistical model as the strength of evidence.

In terms of adoption of the new paradigm, two of the most advanced branches of forensic science are forensic DNA and forensic voice comparison. We have particular expertise in these branches of forensic science, plus expertise in forensic inference and statistics and in machine learning. We collaborate with researchers and practitioners who have expertise in other branches of forensic science.

We also work on increasing the understanding of forensic inference and statistics among forensic scientists and lawyers.

Structure and formation

network

The Forensic Data Science Laboratory (FDSL) is part of the Computer Science Department, School of Engineering and Applied Science, and part of the Aston Institute for Forensic Linguistics (AIFL). A subunit of FDSL is the Forensic Speech Science Laboratory (FSSL).

The Laboratory was established in 2019 as part of the formation of AIFL. Initial funding for AIFL came from a GBP 5.4 M grant from Research England’s Expanding Excellence in England (E3) programme and a GBP 0.6 M strategic investment by Aston University.

 

 

Leadership

The director of the laboratory is Dr Geoffery Stewart Morrison. Dr Morrison was a leading applicant on the E3 grant that established AIFL. Prior to the formation of the Laboratory, Dr Morrison and his colleagues spent more than a decade promoting and developing implementation of the new paradigm, primarily in forensic speech science.geoff_gmm

Dr Morrison’s former appointments include Director of the Forensic Voice Comparison Laboratory, School of Electrical Engineering & Telecommunications, University of New South Wales, and Scientific Counsel, Office of Legal Affairs, INTERPOL. He is author of more than 50 academic publications, and has been a subject editor and a guest editor for the journals Speech Communication and Science & Justice. He is Chair of the Forensic Science Committee of the British Standards Institution (BSI), and an active member of the Forensic Science Committee of the International Organization for Standardization (ISO) and of the Speaker Recognition Subcommittee of the Organization of Scientific area Committees for Forensic Science (OSAC). He has forensic casework experience in Australia, Canada, Northern Ireland, Sweden, and the United States.

Joining us in May 2020, the Deputy Director of the Laboratory will be Dr Roberto Puch-Solis. Dr Puch-Solis has almost two decades of experience in forensic data science. During this time he has conducted research on glass, fibres, fingerprints, and DNA. His primary research is in evaluation of DNA profiles. He has lead the development of probabilistic systems for the evaluation of DNA profiles, including a probabilistic genotyping system that is currently used in casework.

Dr Puch-Solis’s former appointments include Statistician in the Interpretation Group of the Forensic Science Service, and Lead Statistician at LGC Forensics and Eurofins Forensic Services. His experience in these roles includes conducting research and development, conducting forensic casework, providing casework support, providing training, and providing internal and external consulting services

 

News and events

Postdoc opportunity

updated 2020-02-16

Marie Skłodowska-Curie Individual Fellowships (H2020-MSCA-IF-2020)

We are fully eligible to apply this year, but this may be the last opportunity. The submission deadline is 2020-09-09, but we have much earlier internal deadlines for developing the application. If you want to work with us, contact us as soon as possible. Send 
Dr Morrison a pdf of your CV and a one-page pdf explaining what you want to do.

Fellowships are two years (max) in duration. Candidates must have a PhD or 4 years of research experience, and must have a strong CV. Candidates can come from anywhere in the world, but must not have spent more than 12 months of the previous three years in the UK. There are no age restrictions, but it must be clear how the candidate will achieve career development, so they will usually be early to mid career.

Deputy Director appointed

updated 2020-02-01

We are happy to announce that Dr Roberto Puch-Solis has been appointed as Deputy Director of the Forensic Data Science Laboratory. Dr Puch-Solis has expertise in forensic inference and statistics, particularly applied to evidential evaluation of DNA profiles. He begins working with us on May 1, 2020.

Postdoctoral researchers appointed

updated 2020-03-14

We are happy to announce that we have appointed two postdoctoral researchers. Dr Philip Weber has a background in machine learning and speech processing. He began working with us on January 1, 2020. Dr Nabanita Basu has a background in machine learning and forensic science. She began working with us on March 8, 2020. 

Video lectures on statistical models in forensic voice comparison

updated 2020-01-01

Videos of lectures by Dr Morrison on MFCCs, GMM-UBM, calibration models, i-vectors, PLDA, and x-vectors have been posted at http://handbook-of-forensic-statistics.forensic-voice-comparison.net/. A preprint of a book chapter on statistical models in forensic voice comparison is also available at that URL.

People

Researchers

Dr Nabanita Basu 
Member of the Forensic Data Science Laboratory
Research Associate in Forensic Data Science, Computer Science Department, Aston University

Dr Diego Faria
Member of the Forensic Data Science Laboratory 
Senior Lecturer in Computer Science, Computer Science Department, Aston University

Dr Patrick Geoghegan
Member of the Forensic Data Science Laboratory 
Lecturer in Biomedical Engineering, Biomedical Engineering Department, Aston University

Dr Geoffrey Stewart Morrison
Director of the Forensic Data Science Laboratory, Director of the Forensic Speech Science Laboratory
Associate Professor of Forensic Speech Science, Computer Science Department, Aston University

Dr Roberto Puch-Solis
Deputy Director of the Forensic Data Science Laboratory
Senior Lecturer in Forensic Data Science, Computer Science Department, Aston University

Ms Aleksandra Szczekulska
Research Assistant in the Forensic Speech Science Laboratory
Student in MA Forensic Linguistics Programme, Aston University

Dr George Vogiatzis
Member of the Forensic Data Science Laboratory 
Senior Lecturer in Computer Science, Computer Science Department, Aston University

Dr Philip Weber
Member of the Forensic Data Science Laboratory, Member of the Forensic Speech Science Laboratory
Research Fellow in Forensic Data Science, Computer Science Department, Aston University

Adjunct Researchers

Dr Rachel Bolton-King
Visiting Research Fellow in the Forensic Data Science Laboratory
Associate Professor of Forensic Science, Department of Criminal Justice and Forensic Science, Staffordshire University

Dr Ewald Enzinger
Visiting Research Fellow in the Forensic Speech Science Laboratory
Senior Research Engineer, Eduworks Corporation

Dr Claudia Rosas
Visiting Research Fellow in the Forensic Speech Science Laboratory
Associate Professor, Instituto de Lingüística y Literatura, Universidad Austral de Chile

Dr Rolf Ypma
Visiting Research Fellow in the Forensic Data Science Laboratory
Forensic Data Scientist, Netherlands Forensic Institute

Prof Cuiling Zhang
Visiting Research Fellow in the Forensic Speech Science Laboratory 
Director, Chongqing Institutes of Higher Education Key Forensic Science Laboratory; Professor and Vice Dean, School of Criminal Investigation, Southwest University of Political Science and Law

Research and development projects

The following research and development projects are in progress or under development

Forensic speech science: Development of a forensic voice comparison system

updated 2020-02-09

mfcc

Laboratory members and adjunct members working on this project: Dr Morrison, Dr Weber, Ms Szczekulska, Dr Enzinger, Prof Zhang, Dr Rosas

We are developing a forensic voice comparison system that can be used for research and casework. We view a system for conducting forensic voice comparison as not simply a collection of tools, but also protocols, databases suitable for training and testing under casework conditions, documentation, validation reports, and well-trained practitioners. We aim to develop a system that will meet legal admissibility requirements such as those of Federal Rule of Evidence 702 and the Daubert trilogy of Supreme Court rulings in the United States, and of Criminal Practice Directions 19A in England & Wales.

In forensic voice comparison casework, the relevant population and the recording conditions vary greatly from case to case. Researchers and practitioners need protocols, tools, and data that provide them with the flexibility to deal with this case-to-case variability. Practitioners need to be able to train (or adapt) the system for the conditions of the case, and they need to be able to empirically validate the performance of the system under conditions reflecting those of the case. In order to inform practice, researchers need to explore which options and settings give best performance under particular conditions, and explore the robustness of systems to variability in conditions.

Commercially marketed software tools often lack flexibility, and may be too expensive for researchers and practitioners in lower GDP countries. Many researchers and practitioners in the field lack the programming skills to make use of existing open-source automatic speaker recognition toolsets, and licencing restrictions may prevent such toolsets from being used for casework which counts as commercial activity. For different reasons, existing commercial and open-source tools are often insufficiently well documented for end users and others to be able to easily understand what the tools are actually doing. This is in opposition to the transparency that may be required by the courts. Researchers and practitioners therefore need software tools that are low cost, flexible, and easy to use (controllable via GUI or only requiring very limited programming skills), that are very well documented, that are designed to facilitate validation, and that have code that is open to inspection (we envisage open source, but not open distribution).

In the context of this research and development project, we define two groups of end-users: 1. Researchers and practitioners who will (potentially) use the system to do research and to conduct casework. 2. Service users, i.e., organizations that commission practitioners to perform forensic voice comparison analyses. Potential service users include defence lawyers and law-enforcement agencies.

This project is conducted in collaboration with several partner organizations, including:

  • Chile: 
    Universidad Austral de Chile 
    Policía de Investigaciones
    principal collaborator: Dr Claudia Rosas

  • China: 
    Southwest University of Political Science and Law
    principal collaborator: Prof Cuiling Zhang

  • Germany: 
    German Federal Police, Bundeskriminalamt (BKA) 
    principal collaborator: Dr Michael Jessen

  • Netherlands: 
    Netherlands Forensic Institute (NFI) 
    principal collaborator: Mr David van der Vloed

  • Sweden
    Swedish National Forensic Centre (NFC) 
    principal collaborator: Ms Fanny Carlström Plaza

  • United Kingdom:
    National Crime Agency (NCA)

  • United States of America:
    Federal Bureau of Investigation (FBI) 
    principal collaborator: Mr David Marks

Progress:

  • 2018–2019 we worked with partners and collaborators on end-user needs assessments in order to identify the data that need to be collected, and the software tools, protocols, and training programmes that need to be developed.

  • 2018–2019 we developed prototypes for core software tools.

  • 2020 Jan–Feb: Consolidated end-user needs assessment and draft of functional requirements completed and distributed to partners and collaborators for feedback.

Funding: Research England, Expanding Excellence in England (E3)

Forensic speech science: Consensus on validation of forensic voice comparison

updated 2020-03-14

Tippett

Laboratory members and adjunct members working on this project: Dr Morrison, Dr Enzinger, Dr Ypma.

Since the 1960s, there have been calls for forensic voice comparison to be empirically validated under casework conditions. Since around 2000, there have been an increasing number of researchers and practitioners who conduct forensic-voice-comparison research and casework within the likelihood-ratio framework. In recent years, this community of researchers and practitioners has made substantial progress toward validation under casework conditions becoming a standard part of practice: They have developed procedures, metrics, and graphics for validating forensic voice comparison systems and reporting the results. The Speech Communication virtual special issue on validation of forensic voice comparison systems was completed in 2019. There is also an ongoing effort through the Organization of Scientific Area Committees for Forensic Science (OSAC) to develop a standard for validation of forensic voice comparison systems.

An outstanding question is:

  • Given the results of an empirical validation of a forensic-voice-comparison system, how can one decide whether it is good enough to be used in court?

In September 2019 we held a two-day meeting to discuss this issue. The meeting was organized and sponsored by the Forensic Speech Science Laboratory (Aston University), and hosted by the Netherlands Forensic Institute (NFI).

Invited were a group of participants who could potentially produce a document that would be seen as representing what is “generally accepted within the relevant scientific community”. Invitees were individuals who have knowledge and experience of validating forensic voice comparison systems in research and casework contexts, and individuals who have actually presented validation results to courts. Also invited were individuals who could bring a legal perspective on the issue, and individuals with knowledge and experience of validation of forensic science more broadly.

The issue was discussed:

  • from an admissibility perspective, e.g., in the US with respect to FRE 702 and the Daubert trilogy, and in England & Wales with respect to CPD 19A.

  • with respect to jurisdictions and situations in which formal admissibility criteria do not apply but in which knowledge of validation results should be relevant for the court.

  • from a laboratory procedure or best practice perspective – should the practitioner proceed to analyze the questioned- and known-speaker recordings?

During the meeting, a consensus was reached among those in attendance.

An initial draft of a document describing the consensus was written, and in December 2019 was distributed to meeting attendees. The draft is now being revised using a cyclical process involving videoconference meetings and document revision. The process will later be expanded to include original invitees who were unable to attend the original meeting.

The plan is to submit the final version of the document for publication open-access in a reputable forensic science journal.

Funding: Research England, Expanding Excellence in England (E3)

DNA: Statistical evaluation of DNA profiles

updated 2020-02-19

DNA_electropherogram

Laboratory members and adjunct members working on this project: Dr Puch-Solis, Dr Morrison

This project will extend Dr Puch-Solis’s existing work on evaluation of DNA profiles. It will include comparison of different approaches to probabilistic genotyping.

It will also include transfer of concepts, techniques, and models (e.g., for calibration) from forensic speech science to evaluation of DNA profiles.

Funding: Research England, Expanding Excellence in England (E3)

 

 

 

Firearms: Calculation of likelihood ratios from forensic comparison of fired cartridge casings

updated 2020-02-08

Ruger_P85_Fired_Cartridge_Case

Laboratory members and adjunct members working on this project: Dr Bolton-King, Dr Basu, Dr Vogiatzis, Dr Morrison

During 2020, Dr Bolton-King and her collaborators are creating a database of scans of 9 mm Luger type cartridge casings fired from semi-automatic pistols. The aim is to scan 10 cartridges fired from each of 1000 pistols (10,000 cartridges total). The scans are being made using an Evofinder Data Acquisition System.

We will exploit the database to develop and validate a system that uses image-processing and machine-learning techniques to calculate likelihood ratios, likelihood ratios addressing the hypotheses that questioned- and known-origin cartridge casings were fired from the same pistol versus that they were fired from different pistols (pistols that fire 9 mm Luger type ammunition).

Funding: Research England, Expanding Excellence in England (E3)

 

Gait analysis: Calculation of likelihood ratios from forensic comparison of video recordings of walkers

gait-gomi400x300-with-borderupdated 2020-02-08

Laboratory members and adjunct members working on this project: Ms Szczekulska, Dr Geoghegan, Dr Faria, Dr Morrison

In collaboration with Prof Egbert Otten and Ms Marie Wiedemeijer, Center for Human Movement Sciences, University of Groningen, we are developing a project on forensic gait analysis.

We will build on Prof Otten and Ms Wiedemeijer’s existing work that calculates likelihood ratios using features that are visually extracted from video images by human coders. We plan to collect larger forensically relevant databases, attempt to make improvements in statistical modelling, and conduct validation studies. We also plan to explore automatic extraction of features.

 

Fingerprints: Calculation of likelihood ratios from fingermark and fingerprint images

Laboratory members and adjunct members working on this project: Dr Puch-Solis, Dr Basu, Dr Vogiatzis, Dr Morrison

We are developing a research project on calculating likelihood ratios for comparisons of fingermarks and fingerprint images. 

 

Publications

Recent forensic science publications authored by Laboratory members

updated 2020-02-09

  • Morrison G.S., Enzinger E., Ramos D., González-Rodríguez J., Lozano-Díez A. (2020). Statistical models in forensic voice comparison. In Banks D.L., Kafadar K., Kaye D.H., Tackett M. (Eds.), Handbook of Forensic Statistics (Ch. 21). Boca Raton, FL: CRC. (Preprint and videos at: http://handbook-of-forensic-statistics.forensic-voice-comparison.net/)

  • Rosas C., Sommerhoff J., Morrison G.S. (2019). A method for calculating the strength of evidence associated with an earwitness’s claimed recognition of a familiar speaker. Science & Justice, 59, 585–596. https://doi.org/10.1016/j.scijus.2019.07.001

  • Morrison, G.S., Enzinger, E. (2019). Multi-laboratory evaluation of forensic voice comparison systems under conditions reflecting those of a real forensic case (forensic_eval_01) - Conclusion. Speech Communication, 112, 37–39. https://doi.org/10.1016/j.specom.2019.06.007

  • Morrison, G.S., Kelly, F. (2019). A statistical procedure to adjust for time-interval mismatch in forensic voice comparison. Speech Communication, 112, 15–21. https://doi.org/10.1016/j.specom.2019.07.001

  • Morrison G.S., Enzinger E. (2019). Introduction to forensic voice comparison. In Katz W.F., Assmann P.F. (Eds.) The Routledge Handbook of Phonetics (ch. 21, pp. 599–634). Abingdon, UK: Taylor & Francis. https://doi.org/10.4324/9780429056253

  • Morrison G.S., Ballantyne K., Geoghegan P.H. (2018). A response to Marquis et al (2017) What is the error margin of your signature analysis? Forensic Science International, 287, e11–e12. https://doi.org/10.1016/j.forsciint.2018.03.009

  • Morrison G.S. (2018). Admissibility of forensic voice comparison testimony in England and Wales. Criminal Law Review, (1), 20–33. (Preprint at: http://geoff-morrison.net/#Admissibility_EW_2018)

  • Morrison G.S., Enzinger E., Zhang C. (2018). Forensic speech science. In Freckelton I., Selby H. (Eds.), Expert Evidence (Ch. 99). Sydney, Australia: Thomson Reuters. (Preprint at: http://expert-evidence.forensic-voice-comparison.net/)

  • Morrison G.S., Poh N. (2018). Avoiding overstating the strength of forensic evidence: Shrunk likelihood ratios / Bayes factors. Science & Justice, 58, 200–218. http://dx.doi.org/10.1016/j.scijus.2017.12.005

  • Morrison G.S. (2018). The impact in forensic voice comparison of lack of calibration and of mismatched conditions between the known-speaker recording and the relevant-population sample recordings. Forensic Science International, 283, e1–e7. http://dx.doi.org/10.1016/j.forsciint.2017.12.024~

  • Morrison G.S., Enzinger E. (2018). Score based procedures for the calculation of forensic likelihood ratios – Scores should take account of both similarity and typicality. Science & Justice, 58, 47–58. http://dx.doi.org/10.1016/j.scijus.2017.06.005

 

Training

Continuing professional development (CPD)

workshop300x225-with-border



Day-long CPD workshops we offered at Aston University include those listed below.

We can also provide shorter or longer workshops either at Aston University or at your facilities. If you have particular training needs, please contact Dr Morrison to discuss options.

 

 

 

Introduction to the likelihood ratio framework for evaluation of forensic evidence

updated 2020-02-09

Presenter: Dr Geoffrey Stewart Morrison

Target audiences: lawyers and forensic scientists
Duration: 4–5 hours, plus lunch break

Date and time of next workshop: TBA
Registration deadline: TBA
Registration link: TBA

Abstract:

Among experts in forensic inference and statistics the likelihood-ratio framework is widely regarded as the logically correct framework for evaluation of forensic evidence, but there is a great deal of misunderstanding about likelihood ratios among lawyers and forensic scientists.

The likelihood-ratio framework makes explicit the questions which must logically be addressed by the forensic scientist and considered by lawyers, judges, and trier’s of fact in assessing the work of the forensic scientist.

This workshop explains the logic of the likelihood-ratio framework in a way which is accessible to a broad audience and which does not require any prior knowledge of the framework. It uses intuitive examples and audience-participation exercises to gradually build a fuller understanding of the likelihood-ratio framework.

Feedback from previous workshops:

“I have attended several presentation on the likelihood-ratio framework over the last few years. Yours was the first that actually made it understandable.”

“I obtained great value from this workshop which was: Very well arranged. Structure was excellent. Pacing was good. Learning feedback opportunities were numerous.”

“Interactive, small group, whole day workshop, plenty of time for questions, speaker was knowledgeable and funny. Excellent all round.”

“It was nice to see how the likelihood ratio applied to real forensic evidence contexts and working through examples helped me to understand and practice the concepts. It was helpful to work through simple and fun examples to ease into the more complex forensic problems.”

“I liked the structure of the workshop - how we started with basic concepts and applied those to scientific data. The presentation was clear and very useful. I also liked the exercises after the presentation, which helped to put the theory into practice and test our knowledge. Highly enjoyable.”

Assessing the probative value of DNA evidence

updated 2020-02-09

Presenter: Dr Roberto Puch-Solis

Details TBA

MSc Forensic Data Science

LDA

updated 2020-02-09

We plan to develop a Master’s degree in Forensic Data Science. The programme would include core courses in forensic inference and statistics and in machine learning, and also allow students to specialize in application in particular branches of forensic science, including forensic speech science. We may offer individual courses as extended CPD training, for which credit could potentially be given if the participant later enrols in the whole MSc programme. We may offer the programme with a part-time option and as a mixture of distance education and intensive on-site teaching. This would facilitate participation by students from around the world who may already be employed in forensic science and who want to upgrade their skill set. 

Standards development

Standards development

standardsThough his position as Chair the Forensic Science Committee of the British Standards Institution (BSI) and his active participation in the Forensic Science Committee of the International Organization for Standardization (ISO), Dr Morrison is contributing to the development of ISO 21043 Forensic Science: Part 3 Analysis, Part 4 Interpretation, and Part 5 Reporting.

In the Speaker Recognition Subcommittee of the Organization of Scientific area Committees for Forensic Science (OSAC), Dr Morrison is leader of a task group that is developing a multi-part standard for forensic speaker recognition, including parts on Evaluation of evidence for the purpose of informing legal decision making, and on Validation of forensic speaker recognition for the purpose of informing legal admissibility decisions.