ISHI 2018 Workshop on Systems Thinking and Forensic DNA Validation with Drs. Butler, Cotton, Grgicak and Word

This workshop introduces systems thinking with demonstrations on applying a systems approach to forensic DNA mixture interpretation, optimization and validation. Topics to be covered include validation of the DNA interpretation pipeline containing probabilistic genotyping software, focusing on current and forthcoming OSAC/ASB and SWGDAM mixture interpretation validation and verification standards and guidelines. Also included will be a review of published literature with discussions on the foundational validity of mixture interpretation and the impact of laboratory accreditation. Future directions for improving front end processing steps will also be discussed.

LFTDI Article on Estimating the Number of Contributors using Allele Counting Published in Legal Medicine

Drs. Grgicak and Lun along with Sarah E. Norsworthy publish an article entitled “Determining the number of contributors to DNA mixtures in the low-template regime: Exploring the impacts of sampling and detection effects” in Legal Medicine (DOI: https://doi.org/10.1016/j.legalmed.2018.02.001). 

We show that capturing all of the information has positive impacts on inference while allele counting methods lead to underestimations.

Go to Article

 

Dr. Grgicak speaks at the NIJ R&D Symposium

The Forensic Technology Center of Excellence (FTCoE) will assist the National Institute of Justice (NIJ) in hosting the annual NIJ Forensic Science Research and Development (R&D) Symposium on February 20th, 2018 at the 70th Annual American Academy of Forensic Sciences (AAFS) meeting in Seattle, WA. The NIJ Forensic Science R&D Symposium is a free and open meeting where attendees learn about NIJ-funded research across a variety of forensic science areas.

Afternoon Session II: Forensic Biology/DNA

Dr Grgicak will present LFTDI’s work pertaining to ValiDNA in a talk entitled

? Production of High-Fidelity Electropherograms Results in Improved and Consistent Match-Statistics: Standardizing Forensic Validation by Coupling Laboratory Specific Experimental Data with an In Silico DNA Pipeline

Paper describing ReSOLVIt published in FSI:Genetics

We modify our full in silico DNA pipeline to focus on resolving signal-to-noise within the single-copy regime.

The paper describes system design and ways in which the system can be implemented into forensic DNA validation and optimization.

http://www.sciencedirect.com/science/article/pii/S1872497317301916

Paper Highlights

•An in silico DNA system is parameterized with the laboratories own experimental data, resulting in predictions of optimal laboratory settings.
•Noise and allele peak height distributions from a single copy of DNA are used to assess signal-to-noise resolution.
•Optimal signal detection thresholds, or analytical thresholds, for casework are obtained, if necessary.
•We demonstrate that metrics of signal quality for simulated and experimental data are consistent.
•This is a systematic method for evaluating EPG quality and is a critical step towards standardizing the post-PCR process.

Drs. Lun & Grgicak speak to the Legal Aid Society

On October 26th, 2017 we will speak at a conference hosted by the Legal Aid Society. See our calendar of events for location and other details.

Dr. Desmond Lun will be speaking on our research pertaining to the development of computational methods in forensic science.

Dr. Catherine Grgicak speaks about signal quality and effects on continuous Likelihood Ratios.