David Wilson is a well known criminologist and former prison governor. Clare meets him in the village of Wicken on the Northamptonshire/Buckinghamshire border near to where he lives for a walk to the nearby village of Leckhampstead. This is one of David's regular routes. He has been walking around 50 miles a week since lockdown began in March. He does it to keep his weight down and to help process the horrors he often faces in his work dealing with murderers and serial killers. Clare talks to him about a case in his hometown in Scotland which he has recently written a book about. In it he reexamines the brutal murder of a young woman in 1973. Many people in the town believed the wrong man was tried and convicted. With the help of his sisters, David revisits the case and tracks down the man he believes to be the real killer.

Producer: Maggie Ayre

The route starts on OS Landranger 152 Grid Ref SP 745394 Wicken to Leckhampstead