8-hour workshop held at the National Institute of Standards and Technology (Gaithersburg, MD)

and webcast (see http://www.nist.gov/oles/forensics/dna-analyst-training-on-mixture-interpretation.cfm)


Friday, April 12, 2013


Organized by John Paul Jones II,

NIST Law Enforcement Standards Office



John M. Butler, PhD             National Institute of Standards and Technology

Michael D. Coble, PhD        NIST, Applied Genetics Group

Robin W. Cotton, PhD         Boston University, Biomedical Forensic Sciences

Bruce J. Heidebrecht, MS   Maryland State Police, Forensic Sciences Division

Charlotte J. Word, PhD       Consultant

To view or print slide handouts (6-slides to a page), click on here.


Example Profiles





Times (approximate)







Introduction and Need



8:30 - 8:35 a.m.



John Paul Jones II

8:35 - 9:00 a.m.

History - Why There’s a Need for Improvement and Training

Robin Cotton


Fundamental Principles of Interpretation and Statistics


9:00 - 9:45 a.m.

Introduction to Interpretation Issues (thresholds)

John Butler

9:45 - 10:30 a.m.

Statistical Approaches

Mike Coble


10:30 - 10:45 a.m.



Worked Examples and Report Wording


10:45 a.m. - 11:45 a.m.

Worked Examples & Report Wording

Bruce Heidebrecht

11:45 a.m. - 12:15 p.m.

Different Assumptions & Different Interpretations

Charlotte Word


12:15 - 1:00 p.m.



Complex Mixtures, Software, and SOPs



1:00 - 2:00 p.m.

Complex Mixtures (3 & 4 person, relatives)


Charlotte Word

2:00 - 2:45 p.m.

Probabilistic Genotyping

Mike Coble

2:45 - 3:15 p.m.

Updating SOPs and Improving the Lab Process

Bruce Heidebrecht


3:15 - 3:30 p.m.



Low Level DNA Mixtures and Validation



3:30 - 4:10 p.m.

Low Temple DNA Challenges and Validation Suggestions


John Butler


Court Testimony



4:10 - 5:00 p.m.

Court and Expert Witness Testimony


Robin Cotton


Perspectives on the Future



5:00 - 5:30 p.m.

What We Have Learned and Recent Literature


John Butler



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Revised: 04/11/2013