Dr John Bond's method of identifying fingerprints on brass bullet-casings, even after they have been wiped clean, was based on the minuscule amounts of corrosion which can be caused by sweat.
First announced in 2008, this breakthrough was cited as one of the technologies 'most likely to change the world' by a panel of experts for BBC Focus magazine and was included in Time magazine's list of '50 best inventions of the year'.