The DNA Revolution: How Alec Jeffreys Changed Crime Fighting Forever

On the morning of September 10, 1984, Dr. Alec Jeffreys was studying a piece of X-ray film in his laboratory at the University of Leicester. The film showed bands of DNA from members of his technician's family. What he saw stopped him cold: every person's DNA produced a completely unique pattern.

"It was a eureka moment," Jeffreys later recalled. "In 10 minutes I realized the potential for human identification."

THE DISCOVERY: Jeffreys had developed a technique he called "DNA fingerprinting" — a method of analyzing specific regions of DNA that vary significantly between individuals. No two people (except identical twins) share the same profile.

THE FIRST CRIMINAL CASE — EXONERATION: In 1986, police investigating the rape and murder of two young girls in Leicestershire asked Jeffreys to test a local man who had confessed: Richard Buckland. The DNA test proved the confession was false. Buckland became the first person in the world to be exonerated by DNA evidence.

THE FIRST CRIMINAL CASE — CONVICTION: Police then collected DNA from over 5,000 men in the area. One man, Colin Pitchfork, paid a colleague to give a sample in his name. When that colleague mentioned it in a pub, someone told police. Pitchfork was arrested in 1987 and became the first person in the world convicted using DNA evidence.

THE REVOLUTION: Since 1987, DNA evidence has:

• Solved hundreds of thousands of murders, rapes, and other crimes
• Exonerated over 375 wrongfully convicted people in the U.S. alone
• Transformed forensic science worldwide

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