#326 How DNA Solves Crimes: The Forensic Science Behind True Crime

True crime dominates the podcasting world, but what about the genetic aspects behind these cases? In this episode of DNA Today, we dive into the pivotal role of DNA in forensic science with Dr. Henry Erlich, a pioneer in DNA analysis and a key figure in developing polymerase chain reaction (PCR) technology. His work has transformed the criminal justice system, from solving cases to overturning wrongful convictions.

Dr. Henry Erlich has authored over 450 publications and spent decades applying DNA analysis to criminal investigations, missing persons cases, and ancestry research. His lab performed the first DNA case in the US and, in 1988, the first DNA exoneration. Erlich was the Director of the Department of Human Genetics and Vice-President of Discovery Research for Roche Molecular Systems, Inc until 2013. He is currently a Senior Scientist at Benioff Children’s Hospital Oakland Research Institute. He has published > 450 articles and is the recipient of numerous awards.

After reading his book Genetic Reconstruction of the Past, I had countless questions about how PCR reshaped the justice system, its impact on exonerations, and the ethical implications of forensic DNA databases.

Trigger Warning: This episode contains discussions of murder and sexual assault, which may not be suitable for young listeners.

Topics Covered:

• The development of PCR technology and its revolutionary impact on forensic genetics
• How PCR outperformed older methods like RFLP in criminal case investigations
• Pennsylvania vs. Pestinikas (1986), the first criminal case using DNA analysis
• Key forensic DNA terms explained: inclusion, match, exclusion, and random match probability
• The role of DNA evidence in exonerations and wrongful convictions
• How forensic labs analyze DNA from multiple individuals at crime scenes
• The establishment of the FBI’s National DNA Index System (NDIS) and who is included
• The ethical concerns surrounding partial DNA matches and familial searching
• How public DNA databases like GEDmatch helped identify the Golden State Killer
• Dr. Erlich’s insights into the O.J. Simpson case and its impact on public perception of forensic DNA

Resources and Links:

• Read Genetic Reconstruction of the Past by Dr. Henry Erlich
• Explore the National DNA Index System (NDIS) and CODIS
• The Innocence Project: Fighting wrongful convictions with DNA evidence
• GEDmatch and its role in forensic investigations

Get ready, genetic nerds—another brand-new episode of DNA Today drops this Friday! You can always count on us to deliver fresh content every Friday.

While you wait, why not dive into our library of over 300 episodes? Binge them all on Apple Podcasts, Spotify, our website, or wherever you love to listen—just search “DNA Today.”

Prefer watching? We’ve got you covered! For the past four years, we’ve been recording episodes with video, including some filmed at the iconic NBC Universal Stamford Studios. Check them out on our YouTube channel!

DNA Today is hosted and produced by Kira Dineen, MS, LCGC, CG(ASCP)CM . Our Video Lead is Amanda Andreoli. Our Social Media Lead is Kajal Patel. Our Outreach Intern is Liv Davidson. And our logo Graphic Designer is Ashlyn Enokian, MS, CGC.

See what else we are up to on Instagram, X (Twitter), BluSky, Threads, LinkedIn, Facebook, YouTube and our website, DNAToday.com. Questions/inquiries can be sent to info@DNAtoday.com.