In 1996, New Zealand became the second country to establish a national DNA databank when the enabling Act took effect, providing a powerful crime investigation tool. Orignally, the DNA was taken only from blood samples, but the Criminal Investigations (Blood Samples) Act 1995 was amended in 2003 to allow samples from mouth swabs. The world's first national databank was began operations in the U.K. on 10 Apr 1995. A technique discovered in 1984 by Alec Jeffreys shows how individuals could be identified from their DNA based on Restriction Fragment Length Polymorphism. In 1986, Kary Mullis created the Polymeraze Chain Reaction to replicate DNA for analysis. DNA and the Criminal Justice System: The Technology of Justice, by David Lazer (ed.). - book suggestion.