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Search Publications by: John Butler (Fed)

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Displaying 1 - 25 of 203

DNA Mixture Interpretation: A NIST Scientific Foundation Review

December 18, 2024
Author(s)
John Butler, Hariharan Iyer, Richard Press, Melissa Taylor, Peter Vallone, Sheila Willis
Improvements in DNA testing methods have allowed forensic scientists to reduce the quantity of DNA required for profiling an individual. Today, DNA profiles can be generated from a few skin cells. This increased sensitivity has extended the usefulness of

Inconclusive Decisions and Error Rates in Forensic Science

May 4, 2024
Author(s)
Henry Swofford, Steven Lund, Hariharan K. Iyer, John Butler, Johannes A. Soons, Robert M. Thompson, Vincent Desiderio, JP Jones, Robert Ramotowski
In recent years, there has been discussion and controversy relating to the treatment of inconclusive decisions in forensic feature comparison disciplines when considering the reliability of examination methods and results. In this article, we offer a brief

Inconclusive Decisions and Error Rates in Forensic Science

May 4, 2024
Author(s)
Henry Swofford, Steven Lund, Hariharan Iyer, John Butler, Johannes Soons, Robert Thompson, Vincent Desiderio, JP Jones, Robert Ramotowski
Conference Presentation based on technical paper in ERB (Control Number: N2024-0457).

Digital Investigation Techniques: A NIST Scientific Foundation Review

November 21, 2022
Author(s)
James R. Lyle, Barbara Guttman, John Butler, Kelly Sauerwein, Christina Reed, Corrine Lloyd
This document is an assessment of the scientific foundations of digital forensics. We examined descriptions of digital investigation techniques from peer-reviewed sources, academic and classroom materials, technical guidance from professional organizations

Revision of the SNPforID 34-plex forensic ancestry test: Assay enhancements, standard reference sample genotypes and extended population studies

May 3, 2021
Author(s)
John Butler, Manuel Fondevila, Carla Santos, Ana Freire, Christopher Phillips, M Lareu, Peter Vallone
A revision of an established 34 SNP forensic ancestry test has been made by swapping the under- performing rs727811 component SNP with the highly informative rs3827760 that shows a near-fixed East Asian specific allele. We collated SNP variability data for

NIST Scientific Foundation Reviews

December 18, 2020
Author(s)
John M. Butler, Hariharan K. Iyer, Richard A. Press, Melissa Taylor, Peter Vallone, Sheila Willis
The National Institute of Standards and Technology (NIST) is a scientific research agency that works to advance measurement science, standards, and technology and that has been working to strengthen forensic science methods for almost a century. In recent

Decade(s) of Development in Forensic Science

July 15, 2020
Author(s)
John Butler
On November 12, 2019, at a special anniversary conference entitled "Forensic Science: A Decade of Developments" held at the American Association for the Advancement of Science (AAAS), I provided an overview of developments across the forensic science

DNA mixture interpretation principles: insights from the NIST scientific foundation review

July 1, 2020
Author(s)
John Butler, Hariharan K. Iyer, Richard A. Press, Melissa Taylor, Peter Vallone, Sheila Willis
DNA mixture interpretation has become more challenging in recent years due to several factors including submission of more touch evidence samples to aid investigations and generation of more sensitive DNA test results with new STR typing kits. This

DNA Error Rates

December 7, 2016
Author(s)
John Butler
The 1993 U.S. Supreme Court ruling in Daubert vs. Merrell-Dow Pharmaceuticals insists on knowledge regarding error rates and their application when evidence is introduced into court [1]. The 1996 National Research Council (NRC II) report The Evaluation of

DNA Commission of the International Society for Forensic Genetics: Recommendations on the validation of software programs performing biostatistical calculations for forensic genetics applications

September 4, 2016
Author(s)
Michael D. Coble, John S. Buckleton, John M. Butler, Barbara Guttman
The use of biostatistical software programs to assist in data interpretation and calculate likelihood ratios is essential to forensic geneticists and part of the daily case work flow for both kinship and DNA identification laboratories. Previous

Evaluation of Forensic DNA Mixture Evidence: Guidelines for Evaluation, Interpretation, and Statistical Calculations using the Combined Probability of Inclusion

August 31, 2016
Author(s)
Frederick R. Bieber, John Buckleton, Bruce Budowle, John Butler, Michael D. Coble
The evaluation and interpretation of forensic DNA mixture evidence faces greater interpretational challenges due to increasingly complex mixture evidence. Such challenges include: casework involving low quantity or degraded evidence leading to allele and