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Colin Pitchfork and the First DNA Manhunt, Leicestershire 1987

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The first DNA manhunt

In 1986 a seventeen year old confessed to a murder in Leicestershire that he had not committed. A new technique developed by Alec Jeffreys at the University of Leicester showed he was innocent, and a mass screening of five thousand men led to Colin Pitchfork. Anupama explains the science and the procedure.

  • What a DNA profile measures and why relatives look similar
  • Why the first use of the technique was an exoneration
  • How the blood screening worked and how Pitchfork tried to evade it
  • Modern STR profiling compared with the 1987 method
  • Contamination, mixtures and what a lab report really says

The technique that changed everything, told with its proper caveats.

Transcript
Welcome back to Trace Evidence. I am Anupama Raghunathan. Last week we looked at how fingerprints can fail. This week we move to the technique that most people now think of as forensic science itself, DNA. The first time it was ever used in a criminal case, in Leicestershire in 1986, it did something that still surprises my students. It did not catch anyone. It cleared a teenager who had confessed to a murder he did not commit. Only afterwards did police ask more than five thousand men to give blood, and the person responsible was found because he paid a friend to go in his place. We will go through what Alec Jeffreys actually discovered, how a profile is read, and what a modern lab report can and cannot tell a jury. You are listening on Witspeak Podcasts. Let us begin.
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