THE world鈥檚 first database of quartz grains from soil will soon be available to help police in England solve difficult crimes.
Peter Bull and Ruth Morgan at the University of Oxford examined more than 40,000 quartz grains from 1000 locations in England under an electron microscope and found about 40 types of grain. If the same combination of types is found in two samples, it鈥檚 very likely that they come from the same place, they reasoned.
Bull used the database to help police investigate the deaths of two schoolgirls, Holly Wells and Jessica Chapman, in Soham, Cambridgeshire, in 2002. The vacuum cleaner used to clean a car belonging to the man later convicted of the girls鈥� murder contained the same combination of quartz grains as was found where the girls鈥� bodies were discovered. Mud under the car also had a matching combination. 鈥淚t might only be a few grains of quartz, but it鈥檚 another line of evidence,鈥� says Bull.
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The database will be published in the journal Science and Justice later this year. Bull eventually plans to expand it to include samples from all over the world.
