Adam Ruins Forensic Science

Oct 18 2015

In this episode, Adam investigated the truth about lie detectors, fingerprint analysis, eyewitness testimony and much more. Here are the sources he used.


"Humans are complicated. The truth isn’t something you can detect with a machine… Back in the Dark Ages, they would force criminals to hold a red hot iron to see if it burned them. If it did, it meant you were lying."

Trovillo, Paul V. "History of Lie Detection." Journal of Criminal Law and Criminology 29.6 (1939): 848-81. Northwestern University School of Law Scholarly Commons. Web. 




"Truthful people fail polygraphs all the time, just because they’re sweaty and nervous. And all you have to do to beat it is stay super chill. Criminals do it all the time. Some infamous examples include Gary Ridgway, aka the Green River Killer..." 

"The Curious Story of How the Lie Detector Came to Be." BBC News. The BBC, 21 May 2013. Web.

"… and serial killer Charles Cullen, the Angel of Death." 

"Pretending To Be A 'Good Nurse,' Serial Killer Targeted Patients." Fresh Air. WHYY, Philadelphia, Pennsylvania, 15 Apr. 2013. Radio.

"Larson [the inventor of the polygraph] became so horrified by law enforcement’s unscientific use of his device, he would go on to call the polygraph machine, 'a Frankenstein’s monster.'”

Adler, Ken. The Lie Detectors: The History of an American Obsession. New York: Free Press, 2007. Print.

"But no one listened, and ever since people have insisted that the polygraph can do frankly impossible things."

Eells, Josh. "The Lives They Lived." The New York Times Magazine. The New York Times Company, 21 Dec. 2013. Web.

"And that’s awful, because this BS is still embedded in our legal system. Massachusetts uses [the polygraph] to establish probable cause. Florida requires sex offenders take the test."

Florida Criminal Procedures and Corrections, § 948-30 (2012). Web.

"Combined, government agencies test over 70,000 people a year with a century-old piece of pseudoscience [the polygraph]."

Stromberg, Joseph. "Lie Detectors: Why They Don't Work, and Why Police Use Them Anyway." Vox. Vox Media, 15 Dec. 2014. Web.

"Police may not do it intentionally, but they unconsciously bias and alter witnesses’ memories all the time."

"Eyewitness Identification Reform."The Innocence Project. 10 June 2015. Web.

"In the 1980s, a researcher actually found two snowflakes with precisely the same pattern."

Gopnik, Adam. "All Alike." The New Yorker. Conde Nast, 3 Jan. 2011. Web.

"Take the case of Brandon Mayfield. He was arrested for the Madrid train bombings when the world’s top fingerprint experts said he was a perfect match for a print found at the scene."

"The Real CSI." Frontline. PBS. WGBH, Boston, Massachusetts, 17 Apr. 2012. PBS. Web.

"It’s been shown that fingerprint analysts can unconsciously change their evaluations depending on the details of the case."

Russell, Sue. “Bias and the Big Fingerprint Dust-Up.” Pacific Standard. 18 June 2012. Web.

"The FBI recently admitted that when conducting hair strand matches, their experts gave flawed testimony in 90% of cases, and in 94% of death penalty cases."

United States. Federal Bureau of Investigation. The FBI. U.S. Government, 20 Apr. 2015. Web.

"Bite mark analysis is notorious nonsense. Two men were once placed on death row based on bite marks that were likely made by crawfish."

"2 Men Freed in Child Death Bite-mark Cases." NBC News, 29 Feb. 2008. Web.

"You’ve heard how fire investigators detect arson by searching for 'pouring patterns'? Scientists have since shown that those patterns happen in any fire that has a flashover event."

Grann, David. "Trial by Fire." The New Yorker. Conde Nast, 7 Sept. 2009. Web.

"Did you know that in Scandinavia, they have open-air prisons?"

Larson, Doran. “Why Scandinavian Prisons Are Superior.” The Atlantic. Atlantic Media Company. 24 Sept. 2012. Web. 

For More on This Topic 

The Real CSI: PBS’s in-depth documentary series, Frontline investigates the flaws in some of the best-known tools of forensic science.

In this surprising TED Talk, Elizabeth Loftus explains how the slippery nature of memory can have real-world consequences.

The Lie Detectors: Ken Alder’s history of America’s obsession with the polygraph machine. 

Watch Adam explain why lie detectors don't detect lies and why fingerprinting is flawed.