How DNA Solves Crimes

Everything Everywhere Daily: History, Science, Geography & More

The episode explores the transformative history of DNA profiling and its impact on modern forensic science. It traces the technology from Si

Key takeaways

• Sir Alec Jeffreys discovered DNA fingerprinting at the University of Leicester in 1984.
• The case of Richard Buckland demonstrated DNA's power to exonerate suspects wrongly accused of murder.

Main topics

• History of DNA profiling
• Forensic science advancements

Notable quotes

It acts as an instruction manual for our cells, providing the information needed to build proteins and regulate many biological processes.

Conclusion

DNA profiling has fundamentally revolutionized criminal investigations

Transcript preview

Speaker 1 (0:00) For most of human history, identifying the person responsible for a crime depended on witnesses, confessions, and later fingerprints. Then in the late 20th century, scientists developed a technique to identify an individual from microscopic traces left at a crime scene. It's cleared innocent suspects, identified killers decades after their crimes, and transformed modern forensic science. Learn more about DNA profiling, how it works, and how it revolutionized criminal investigations. on this episode of Everything Everywhere Daily. Speaker 3 (0:45) Comprehensive. Speaker 2 (0:46) Witty. Speaker 3 (0:47) Speculative. Critical. Insightful. Profound. Wide-ranging. Hopefully doesn't take itself too, too seriously. Speaker 2 (0:53) I'm David Remnick, and each week on the New Yorker Radio Hour, my colleagues and I try to make sense of what's happening in this chaotic world. I hope you'll join us for the New Yorker Radio Hour wherever you listen to podcasts. Speaker 3 (1:06) Thoughtful. Exquisite. Just, you know, real. Speaker 1 (1:15) As a podcaster, I'm often asked what podcasts I listen to. One of the shows I subscribe to and listen to every week is The Jordan Harbinger Show. The Jordan Harbinger Show is the top podcast that was named Best of Apple in 2018. One of my recent favorite episodes from this summer was the interview he did with Atasa Araxa Abrahamian, who explained how wealthy people can buy second passports overseas. On the show, Jordan dives into the minds of fascinating people, including everyone from athletes, authors, scientists, mobsters, spies, and hostage negotiators. If you like this podcast, you'll probably like the variety and in-depth interviews on The Jordan Harbinger Show. You can't go wrong with adding the Jordan Harbinger show to your rotation. It's incredibly interesting and there's never a dull show. Search for the Jordan Harbinger show. That's H-A-R-B as in boy, I-N as in Nancy, G-E-R on Apple Podcasts, Spotify, or wherever you listen to podcasts. Speaker 1 (2:11) You've probably seen TV shows where forensic science units use DNA to capture a criminal. While what you see on TV might be dramatized, it is based on actual science. DNA profiling analyzes a person's DNA, the molecule that carries genetic information. It acts as an instruction manual for our cells, providing the information needed to build proteins and regulate many biological processes. We inherit DNA from our parents and it influences many of our physical characteristics and inherited traits. In forensic science, DNA profiling involves analyzing selected regions of DNA that vary considerably among individuals. Modern forensics profiling usually examines short tandem repeats, or STRs, at specific locations in the genome. Investigators can then compare the resulting pattern with DNA from a suspect or with profiles stored in a database. This can help investigators identify suspects, exclude innocent people, connect crimes committed by the same person, or establish biological relationships. The development of modern DNA profiling can largely be attributed to the work of British geneticist Sir Alec Jeffreys. In 1984, while conducting research at the University of Leicester, he noticed highly valuable regions of DNA containing repeated sequences known as mini-satellites. Jeffreys realized that the number and arrangement of these repeated sequences varied enormously between individuals, and this variation could be used for identification. Jeffries and his team developed radioactive probes containing short DNA sequences. These probes could bind to particular receptive regions of DNA and reveal patterns that were