Various pollen grains: from left to right Dracophyllum, Coprosma (three views), and Nothofagus (image: Dallas Mildenhall).
Pollen grains and spores are tiny, long lasting and because they readily adhere to almost any surface, can be found just about everywhere. They are also characteristic of both time and place, so just one type of pollen grain or spore can connect a suspect to the scene of a crime.
Dallas Mildenhall is a forensic palynologist at the Institute of Geological and Nuclear Sciences where he uses pollen grain and spores to help solve crimes and rape cases.