0:00 In twenty-four percent of all wrongful convictions in the United States, misleading forensic evidence was a factor.0:08 Last week, you heard the stories of people who lost years to mistaken identity, and today we examine one of the most powerful engines of that injustice: the evidence that was presented as science.0:23 For decades, in courtrooms across the country, experts took the stand.0:29 They presented evidence that seemed irrefutable.0:32 Microscopic hair comparisons that allegedly linked a suspect to a crime scene.0:38 Analyses of bite marks on a victim’s skin, declared to be a unique match, just like a fingerprint.0:46 To a jury, this testimony sounded definitive.0:49 It was presented as fact, as the cold, hard truth.0:53 And it sent hundreds of people to prison.0:56 Here is what those juries were never told.0:59 The scientific foundations for many of these techniques were weak, or in some cases, non-existent.1:07 There were no validated error rates for bite-mark comparison.1:12 There was no way to say for sure that a single hair found at a scene belonged to one person and one person ONLY.1:20 The testimony often exceeded the limits of what the science could actually support.1:27 It gave the appearance of certainty.1:29 And in a courtroom, that appearance is a powerful thing.1:34 The incentive, for prosecutors, was a conviction.1:37 For the so-called experts, it was a career.1:41 The one who lost was the person sitting at the defense table.1:45 The unravelling began quietly, in labs, with the advent of post-conviction DNA testing.1:52 This was a science with verifiable standards and vanishingly small error rates.1:58 And it began to tell a different story.2:01 In case after case, DNA proved that the person convicted by bite marks or hair analysis could not have committed the crime.2:10 Keith Harward, convicted in 1982 on bite-mark evidence, was exonerated in 2016.2:16 Ray Krone, convicted in 1992, was freed in 2002.2:20 Carlton Lewis was exonerated in 2023, after thirty-one years in prison.2:26 The truth was always there, waiting in the biological evidence.2:30 It just took decades for the science to be able to read it.2:35 The problem was never just one bad expert or one flawed test.2:40 It was systemic.2:41 In Canada, the Goudge Inquiry examined the work of a single forensic pathologist, Doctor Charles Smith, whose errors led to multiple wrongful convictions.2:53 The inquiry produced one hundred and sixty-nine recommendations for reform.2:58 In the United States, there is no equivalent federal body.3:03 Texas has a commission to review unreliable techniques.3:07 But for the most part, oversight is a patchwork.3:11 The American Board of Forensic Odontology finally declared a moratorium on using bite-mark evidence in 2016.3:19 That was years after DNA had already proven it was unreliable.3:24 So what does this all add up to?3:26 It adds up to the 635 cases where the National Institute of Justice found that forensic science errors contributed to a wrongful conviction.3:37 It adds up to the fact that in more than half of all the cases overturned by the Innocence Project, faulty science was a key ingredient.3:47 Each of these cases should have been treated as what one expert, Doctor John Morgan, calls a "sentinel event." A warning light.3:57 A signal that the system itself has a deficiency that needs to be fixed.4:02 Because the cost of getting it wrong is measured in human lives.4:07 The goal was never just to prove one person's innocence.4:12 It was to ensure the same mistakes don't happen again.4:16 That work continues, one case, one hearing, one piece of evidence at a time.
