On the morning of Monday September 10th, 1984, Alec Jeffreys, an as yet little-known scientist was looking at a result of an experiment, he’d set running the week previous. He was trying to look at genetic variation between individuals as a way of looking at how diseases might run in families. But what he was about to discover, was a technique that would change the world.

Professor Turi King speaks with those involved in the discovery and its first use in a criminal investigation.