Preparing for Expert Witness Testimony on Probabilistic Genotyping

With approximately half the forensic laboratories in the United States either using a probabilistic genotyping system or in some stage of implementation, cases processed using this method are now making their way through the court systems. Additionally, probabilistic genotyping has been used at the international level for nearly a decade. As you (as a scientist) make […]

Courtroom Testimony for Probabilistic Genotyping

“Ladies and Gentleman of the Jury, Jane Doe’s DNA matches the DNA found on the handle of the knife; therefore, she touched the knife and used it to stab John Doe”.  As much as prosecutors would like that statement to come out of our mouths, that is not the role of the DNA Analyst.  We […]

Database Searching – Taking Mixtures Further than Ever Before

At The Institute of Environmental Science and Research (ESR) we receive approximately 2600 volume crime samples per year and conservatively it is estimated that approximately 45% of these are mixed. These mixtures range from profiles where it is relatively easy to resolve a DNA profile suitable to load onto the Crime Sample Database by conventional […]

Teaching Old and New Dogs Mixture Tricks of the Future

Most forensic DNA analysts old and new have worked with scientists throughout the past that still wax nostalgically about the silver staining years (or other DNA methods that pre-date many of us).  Generally speaking, nearly all DNA training programs involve components of the ‘history of DNA’ that cover the methods that led us to where […]

Probabilistic Genotyping: Magic Hat or Mixture Resolution Tool?

STRmix™ is an invaluable tool for resolving complex mixtures.  Analysts are now able to make conclusions about samples that would previously have been reported as inconclusive, which in turn is leading to more crimes being solved.  When the analysis is conducted properly, the results make sense based on the profile that we are analyzing with […]

NIST to Assess the Reliability of Forensic Methods for Analyzing DNA Mixtures

The National Institute of Standards and Technology (NIST) will undertake a study to assess the reliability of forensic methods for analyzing DNA evidence that, if misapplied, could lead to innocent people being wrongly convicted. The study will focus on DNA mixtures involving three or more people, and on very small quantities of DNA also known […]

NIST Experts Urge Caution in Use of Courtroom Evidence Presentation Method

Two experts at the National Institute of Standards and Technology (NIST) are calling into question a method of presenting evidence in courtrooms, arguing that it risks allowing personal preference to creep into expert testimony and potentially distorts evidence for a jury.   Article originally published on www.nist.gov. Reprinted with permission.     The method involves […]