The A6 murder is a crime which many believe led to a major miscarriage of justice. In August 1961 Michael Gregsten was shot, and his lover Valerie Storie was raped and shot in their car in a layby off the A6 between Luton and Bedford. Gregsten was killed but Storie survived, paralysed from the waist down.

The first suspect was Peter Alphon, a travelling salesman, but at an identity parade Storie picked out another man, known to be innocent. The next suspect was a 25-year old petty criminal, James Hanratty. Storie picked him from an identity parade, and her identification was the main evidence which led to his being hanged in April 1962.

In Who Killed Hanratty? (1971) the journalist Paul Foot concluded that Hanratty was innocent. Foot also revealed that Alphon has repeatedly told him he was the murderer. In 1992, on the 30th anniversary of Hanratty's death, Foot claimed that Alphon, living then in a run-down hotel in the King's Cross district of London, was still confessing to the crime.

On 22 March 2001 James Hanratty's body was exhumed for DNA analysis. The judgment of the Appeal Court was that "... the DNA evidence establishes beyond doubt that James Hanratty was the murderer.".