The discovery of DNA fingerprinting
Alec Jeffreys discovered DNA fingerprinting in September 1984 at the University of Leicester, when an X-ray film from a study of inherited variation revealed patterns in human DNA distinctive enough to identify an individual. What he could not know was that its first criminal test would arrive from villages just down the road.
The first DNA exoneration
By late 1986, Leicestershire police were holding Richard Buckland, a teenager who had confessed to the murder of Dawn Ashworth but denied killing Lynda Mann. Hoping to link him to both crimes, detectives asked Jeffreys to compare Buckland's blood against semen recovered from the two scenes.
Jeffreys' analysis proved two things. The same man had raped and killed both girls, and that man was not Richard Buckland. The first use of DNA evidence in criminal history was an exoneration, a fact that has shaped how the technique is understood ever since: it convicts the guilty and protects the innocent with the same test.
The first mass DNA screening
In January 1987, police did something unprecedented: they asked every man aged 16 to 34 in Narborough, Enderby and Littlethorpe to volunteer a blood sample. More than 5,000 complied over the following months. It was the first mass DNA screening ever attempted, and it nearly failed.
Colin Pitchfork, a bakery worker with prior convictions for indecent exposure, persuaded a colleague, Ian Kelly, to take the test in his place for £200, using a passport altered to carry Kelly's photograph. Kelly gave blood as "Colin Pitchfork" on 29 January 1987, and the killer's name was quietly eliminated from the inquiry.
The screening didn't catch Pitchfork directly, but it forced him into the lie that did.
On 1 August 1987, Kelly was overheard in a Leicester pub telling colleagues what he had done. One of them, Jackie Foggin, reported the conversation to police in September. Kelly was arrested, and on 19 September 1987 detectives arrested Pitchfork at his home in Littlethorpe. His blood was finally tested, and it matched both crime scenes exactly.
How the case changed forensic science
Pitchfork's guilty plea and life sentence in January 1988 established DNA profiling as courtroom-grade evidence. Within a decade the UK launched the National DNA Database (1995), the first of its kind anywhere, and police forces worldwide adopted the technique for everything from cold cases to disaster victim identification.
The case also seeded the ethical debates that still surround genetic evidence: the privacy implications of mass screening, how long profiles of unconvicted people should be retained, and the danger of treating any single forensic technique as infallible. Every one of those conversations began with this case. The Colin Pitchfork case timeline shows how it unfolded.