25 Years of DNA Testing


It was 25 years ago today, at University of Leicester in England, that Sir Alec Jeffreys made the discovery that would revolutionize the criminal justice system – along with several other facets of science and society. Jeffreys pulled an x-ray film from a developing tank on the morning of September 10, 1984, and realized that markings on the sheet identified the three different people involved in the experiment.

He explains in a new BBC video that he didn’t know immediately how important his discovery would be. When he conducted the first DNA profiling in a criminal case in 1986, the implications of the breakthrough became clear.

"We took on the analysis in full expectation we would get nothing back at all,” Jeffries said. “But we got – I confess to my astonishment – a completely clear readout, which was that one of the suspects who had confessed to the murders was not guilty of that crime."

Today, 25 years later, this technology has exonerated 242 people in the United States and many others around the world. It has set a new standard for forensic evidence and is used regularly to apprehend the perpetrators of crimes.  The lessons of DNA exonerations have revealed serious problems in our criminal justice system that cause wrongful convictions and can be addressed through targeted reforms.

And the technology continues to develop. We hope that the next 25 years will bring advances in forensic technology – and in criminal justice reform – to rival the last 25.

BBC America will feature an interview with Barry Scheck in a new segment marking this historic anniversary tonight at 7:00 p.m. EST on World News America.

Check your local listings


Watch the Jeffreys interview here


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