A fragment of the lens from a pair of broken spectacles can be as identifiable as a fingerprint, as Kevin O’Connor discovered to his cost.

A 27-year-old unemployed carpenter, he planned to rob Frederick Bush, a rent-collector neighbour in Ruislip, Middlesex. On NOVEMBER 4th, 1971, Bush was at home checking the rents he had collected, when O’Connor entered quietly by the back door, carrying a pillow-slip and a length of flex. Before donning a stocking mask, he removed his glasses and put them in a pocket. Then he knocked Mr. Bush unconscious, trussed his hands and feet with the flex, put the pillow-slip over his head, and made off with his cash and cheques. On putting on his glasses, however, O’Connor found that one of the lenses was broken.

Mr. Bush’s daughter returned home 30 minutes later to find her father dead. An autopsy established that he had died from chronic bronchitis and heart failure precipitated by his severe head injuries – his skull was abnormally thin.

His spectacles were found lying intact on the floor beside him, together with fragments of another lens. The prescription for the broken lens was traced by the London Optical Company, and details were sent to all opticians in the area. Checking his records, one of them found that the lens had been prescribed for O’Connor, who was traced to Aberdeen and arrested.

Admitting the killing, he said he was unaware that he had hit Mr. Bush so hard until he read a newspaper report of his death. In December 1971 he was convicted of manslaughter and jailed for life.