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Coding a Safer Society Through Computer Interpretation of DNA Evidence

M.W. Perlin and M.M. Legler, "Coding a safer society through computer interpretation of DNA evidence", MATLAB Virtual Conference, Europe and North America, 26-Mar-2014.


Conference webinar presentation (slides and audio), including a computer demonstration.

Video at Mathworks site

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Much DNA evidence goes unused. Sophisticated crime laboratories can produce superb data that human analysts cannot interpret. DNA that is mixed (two or more contributors), damaged (degraded into pieces) or low level (with few molecules present) introduces uncertainty that overwhelms human problem solving. Thus vital evidence in crimes of rape, murder or terror is often understated or pronounced "inconclusive". Public safety is compromised when DNA identifications are not made, criminals remain at large, and preventable crimes are committed.

Mathematical modeling can embrace this uncertainty, expressing data variation in probability equations. Solving these high-dimensional problems with Markov chain Monte Carlo (MCMC) statistical search, a MATLAB® program can explore many thousands of scenarios. The process mathematically separates mixture data into the genetic components (or, "genotypes") of the contributors. Comparing genotype probability distributions calculates a DNA match statistic that can scientifically associate crime scene evidence with criminals. These match numbers are used to arrest suspects, convict the guilty and exonerate the innocent.

This talk describes the scientific development and forensic application of Cybergenetics TrueAllele® Casework, a computer system for interpreting and matching complex DNA evidence. TrueAllele supercomputer automation reanalyzed the World Trade Center DNA data in order to identify victim remains. Validation studies show that TrueAllele is more accurate, sensitive, specific and precise than human data interpretation, preserving information from discarded evidence. A hundred TrueAllele reports have been filed on DNA evidence in serious crimes, while high-tech TrueAllele databases make cold hits to find investigative leads.

TrueAllele mines the crime lab data that taxpayers have already paid for, and completes the DNA process by computing a safer and more just society.


Dr. Mark Perlin is Chief Scientific and Executive Officer at Cybergenetics. He has twenty years experience developing computer methods for information-rich interpretation of DNA evidence, and providing TrueAllele products and services to the criminal justice community. Ten years ago, TrueAllele computation revolutionized the accurate interpretation of complex DNA evidence, showing that mathematics can make DNA identifications when manual examination cannot. More recently, Dr. Perlin has helped bring this objective computer DNA evidence into the courtroom, testifying in state, federal, military and foreign trials. He holds doctoral degrees in Mathematics (City University of New York) and Computer Science (Carnegie Mellon University), and a medical degree (University of Chicago).