DNA Mixture Interpretation: Basic (full day)

Presenters:  Michael Coble, Steven Myers
Date and Time:  Monday August 29th, 9 AM – 6 PM
Course Level:  Basic

DNA Mixture Interpretation: Advanced (full day)

Presenters: Peter Gill, Corina Benschop, Oyvind Bleka
Date and Time: Monday August 29th, 9 AM – 6 PM
Course Level: Advanced

This is an advanced course intended for case-work scientists who alreadyhave some basic experience of mixture analysis and interpretation. Theworkshop will explain the theory relating to the analysis of complex DNAprofiles where the material may be degraded, and consists of mixtures oftwo or more individuals. The likelihood ratio theory will be explained, alongwith basic principles that underpin the models. Different software solutions will be demonstrated: EuroForMix, DNAStatistX, CaseSolver and DNAxs.

The aim of the workshop is to provide sufficient information and support sothat users will be able to run software. To facilitate, we will provideinstructions to enable users to download software onto their computersbeforehand. The workshop will include hands-on exercises using the latestversions of EuroForMix and DNAStatistX using provided exercises and usingparticipants’ own data. Further information is available from the following websites:

Peter Gill | View Bio

Corina Benschop | View Bio

Y Chromosome: YHRD, typing and interpretation (full day)

Presenters: Sascha Willuweit, Lutz Roewer
Date and Time: Tuesday August 30th, 9 AM – 6 PM

Forensic genetic laboratories perform a large amount of STR analyses of theY chromosome, in particular to analyze the male part of complex DNAmixtures. However, the statistical interpretation of evidence retrieved fromY-STR haplotypes is challenging. Due to the uni-parental inheritance mode,Y-STR loci are connected to each other and thus haplotypes show patterns ofrelationship on the familial and population level. This precludes thetreatment of Y-STR loci as independently inherited variables and theapplication of the product rule. Instead, the haplotype frequency needs to beestimated based on collections of individual samples from the relevantpopulation. Such data collections are provided in form of annotateddatabases, for example the Y Chromosome Haplotype Reference Database(YHRD). In forensic casework the probability of a Y-STR match is evaluated either using count or model-based estimators of the profile frequency. The workshop will provide practical exercises and worked examples to get acquainted with the different methods and interpreting tools.

Questions that will be addressed in this workshop:
  • I found a puzzling Y-STR profile. Any help out there?
  • I got a Y-STR match. How can I get a match probability?
  • I am used to counting methods with lineage markers. What about Discrete Laplace?
  • I got a mixture. How does the program Mixture analysis work?
  • I am doing a complicated paternity case. Could I apply the program Kinship analysis?
  • I’ve been asked to identify a victim. How can I infer biogeographical ancestry using Y markers?
  • I don’t care much on populations. What is so special with reference populations used in Y casework ?
  • I have to write a report on a Y-STR match. I need help with the wording.
  • I want to write a research paper. How can I analyze my populations – how does AMOVA work?

Testimony in US Courts (full day)

Presenters:  Charlotte Word, Raymond Valerio, Lewis Buzzell
Date and Time: Tuesday August 30th, 9 AM – 6 PM

MPS Bioinformatics 101: Exploring Massively Parallel Sequencing Data Analysis using the STRait Razor Suite and FDS Tools

Presenters: Jonathan King, Jerry Hoogenboom
Date and Time: Tuesday August 30th, 9 AM – 6 PM
Course Level: This workshop is intended as an introduction for novice users; however, some advanced topics will be discussed.

This workshop will focus on employing the STRait Razor Suite and FDSTools software for analysis of Massively Parallel Sequencing (MPS) data. Attendees will be instructed on the usage of primary (STRait Razor v3 and FDSTools2.0)and secondary analysis (STRait Razor Online) tools to analyze data from commercially available kits. Additionally, guidance will be given for modifying the default settings, developing configuration files for both primary and secondary analysis of laboratory-developed tests (e.g., in-house PCR multiplex assays), and considerations for further processing the output. The strengths of and rationale behind the different methods will be explored by examining the results. This way, attendees will gain a deeper insight into the powers and challenges (and solutions!) that arise from the application of MPS to forensic samples.

Attendees should be familiar with general constructs of DNA markers and formats of standard sequencing data storage file types (e.g., BED, FASTQ, SAM/BAM, etc.). While no formal familiarity with any programming languages(e.g., R, Python, etc.) is required, modification of open-source materials may require some basic understanding of computer programming.

Jonathan King

Jonathan King | View Bio


Presenters: Daniel Kling, Andreas Tillmar
Date and Time: Monday August 29th, 9 AM – 6 PM


Presenters: Katherine Gettings
Date and Time: Monday August 29th, 9 AM – 1 PM


Presenters: Susan Walsh
Date and Time: Monday August 29th, 2 PM – 6 PM


Presenters: Peter Vallone
Date and Time: Monday August 29th, 9 AM – 1 PM

This workshop aims to review and explore the details of various NGS/MPS sequencing methods. Common sequencing methods, kits, and platforms that may be applied to forensic genetic analyses will be discussed. The laboratory workflow steps involved in sequencing library preparation and their specific purposes will be presented. These include: targeted PCR, incorporation of sequencing adapters and unique indices, quantification/normalization of final products prior to sequencing. Examples of the process will be illustrated through forensically-relevant workflows for the sequencing of STRs, SNPs and the mitochondrial genome. Brief examinations of the resulting sequence data will be demonstrated by the instructor using open source and/or commercial software tools. This workshop is intended for attendees with some basic familiarity with sequencing methods and interested in the basic and practical aspects of carrying out sequencing experiments in support of adopting these methods of genetic analysis in their laboratory. Questions related to the scope of the workshop can be directed to the instructor. [peter.vallone@nist.gov]


Presenters: Walther Parson
Date and Time: Monday August 29th, 2 PM – 6 PM

The forensic field has witnessed major developments in mitochondrial DNA (mtDNA) analysis in the past three years, particularly in association with Massively Parallel Next Generation Sequencing (MPS) techniques.

This workshop showcasts the highlights and discusses various issues with the interpretation of MPS-based mtDNA sequences, including validation studies, the interpretation of sequence raw data with particular focus on NUMTs, heteroplasmy, artefacts and mixtures, database searches with EMPOP.

The workshop provides a brief introduction to the mtDNA molecule and field and is thus suitable for beginners and experts. Participants are invited to send challenging samples/cases beforehand to be included in the discussion.

Walther Parson

Walther Parson | View Bio


Presenters: John Butler
Date and Time: Monday August 29th, 9 AM – 1 PM

Science benefits from effective communication of ideas. Research results are shared with others through publications and presentations. Scientific publication involves efforts in reading, writing and reviewing the literature.Editors of peer-reviewed journals rely on input from scientific colleagues to judge the merits of submitted manuscripts. Knowledgeable reviewers providing timely feedback are important for a successful peer-review process. This workshop will share insights based upon editorial experience with Forensic Science International: Genetics as well as extensive writing practice in preparing five textbooks and over 170 research articles and invited book chapters. Reviewing manuscripts is a chance to provide an important service and to influence the scientific community for good. In addition to discussing approaches to reading, writing and reviewing relevant literature, some recent articles covering forensic genetics will be considered and examined.


Presenters: Roland van Oorschot, Bianca Szkuta and Georgina Meakinr
Date and Time: Tuesday August 30th, 9 AM – 1 PM

This workshop will provide a general update on our understanding of factors impacting the transfer, persistence, prevalence and recovery of DNA (DNA-TPPR). Then through a series of exercises explore the identification of potentially relevant factors impacting DNA-TPPR, the identification and use of relevant data to determine probabilities of profile types given particular actions and circumstances, and limitations of the available data. We will also consider areas requiring further research to improve our understanding of DNA-TPPR and availability of relevant probability data, and explore the types of experiments required to address these. This workshop will not be focused on activity level reporting.

Rolan van Oorschot | View Bio


Presenters: Lydie Samie-Foucart and Tacha Hicks
Date and Time: Tuesday August 30th, 2 PM – 6 PM
Course Level: Intermediate

Target audience: DNA reporting officers with experience in writing statements given sub-source level propositions. Participants are expected to have theoretical and practical background in probabilistic reasoning.

The aim of this workshop is to provide a framework allowing to assess and report DNA results when the issue regards not so much the source of the DNA, but the activities from which it resulted. It will be based on the guidelines produced by the DNA commission of the International Society for Forensic Genetics. Using real cases, participants will explore how to take into consideration transfer, persistence and background level of DNA in a transparent, logical and balanced way. The workshop will consist of presentations showing the essential building blocks for interpretation. Through those presentations and exercise(s), participants will develop ways to assign likelihood ratios in such cases and during debriefing will be introduced to Bayesian Networks. During the workshop, difficulties encountered will be explored and practical solutions to these challenges presented: (e.g., how to manage cases when experimental data are limited).

Tacha Hicks

Tacha Hicks | View Bio

Lydie Samie

Lydie Samie | View Bio


Presenters: Hari Iyer, Steven Lund
Date and Time: Tuesday August 30th, 9 AM – 1 PM

Validation – Experimental Design and Analysis using STR-validator

Presenters: Oskar Hansson
Date and Time: Tuesday August 30th, 2 PM – 6 PM
Course Level: This workshop is suitable for DNA analysts/technicians, QA/QC managers, consultants, and other interested individuals. A minimal background in forensic human identification testing would be beneficial. Programming or statistical background is helpful but not required.

Validation of new STR typing kits are often time consuming which can delay implementation of new technology. STR-validator is a free open-source software tool designed to help forensic genetic laboratories evaluate the data. Lectures and demonstrations will exemplify experimental design and efficient evaluation. Examples will highlight quality control of the data and result. The goal is to introduce STR-validator as an efficient tool to analyze validation data in accordance to ENFSI recommendations and SWGDAM guidelines.

Learning Outcomes

  • Understanding the STR-validator framework and its possibilities.
  • Experimental design and analysis according to ENFSI recommendations and SWGDAM guidelines.
  • Documentation and interpretation of the validation result.
  • Demonstration of automated analysis and report generation using R markdown.

Prepare for the workshop [PRELIMINARY]

  1. Download and install the statistical software R (usually installed together with a graphical user interface RGui or RStudio).
  2. Open RGui or RStudio and install the package strvalidator version 2.3.0 or higher by typing install.packages(“strvalidator”, dependencies=TRUE) in the R console, or using the installation menu.
  3. Download the zip file with exercises and unpack to a folder of your choice.
  4. It is recommended that you follow the instructions in the installation guide to create an icon for STR-validator in your folder.

Links: STR-validator website

Related publications

Coauthor of the book  Forensic Practitioner’s Guide to the Interpretation of Complex DNA Profiles – 1st Edition (elsevier.com).

Fun fact

In 1999, age 20, I attended an apnea (free diving) course in Båstad (Sweden) hosted by Jean-Jacques Mayol, son of  Jacques Mayol – Wikipediawho’s life inspired the famous film The Big Blue – Wikipedia .  Jean-Jacques Mayol is still teaching a combination of Apnea and Yoga, but now located in Italy at his late father’s home  Teammayol.


Oskar Hansson | View Bio


Presenters: Torben Tvedebrink
Date and Time: Tuesday August 30th, 9 AM – 1 PM

In recent years, biogeographical ancestry markers have gained attention in the forensic genetics community with their ability to associate geographical and ethnic origins to DNA samples. Ancestry Informative SNP (AISNP) markers and panels have been selected and designed in order to provide investigational leads and for predicting the geographical origin of the investigated individuals in crime and identification cases. There exists several methods for modelling AISNPs, including principal components analysis (PCA), model based clustering (e.g. implemented in the software STRUCTURE and ADMIXTURE) and classification methods. However, a common assumption of these approaches is that a true population exists in the reference material. Using a statistical based outlier detection approach (implemented in Genogeographer: http://genogeographer.org, [1, 2]) this assumption is not needed. The workshop will discuss the strengths and weaknesses of the listed methodologies, introduce the participants to the ideas behind genogeographer.org, and show how to use this tool in relation to casework.

Genogeographer references:[1] T. Tvedebrink et al. (2018) Weight of the evidence of genetic investigations of ancestry informative markers. Theoretical Population Biology 120: 1–10[2] T. Tvedebrink et al. (2017) GenoGeographer – A tool for genogeographic inference. Forensic Science International: Genetics Supplement Series 6: e463-e465

Torben Tvedebrink

Torben Tvedebrink | View Bio

Special Sessions

The O.J. Simpson Trial:  A Retrospective

It has been over 25 years since O.J. Simpson was acquitted of the murder of his ex-wife Nicole Brown Simpson and her friend Ronald Goldman, yet this case remains one of the most notorious criminal trials in American history…


Robin Cotton, PhD; expert witness (DNA) in People v. O.J. Simpson
Bruce Weir, PhD; expert witness (statistics) in People v. O.J. Simpson
Rockne Harmon; prosecutor in People v. O.J. Simpson
Barry Scheck; defense attorney in People v. O.J. Simpson

Learn More