Genetic databases have been created in several countries: the United Kingdom was the first European country to have, in 1995, a DNA database. Subsequently, the Netherlands and Austria (1997), Germany (1998), Finland and Norway (1999) and many others have introduced or are preparing databases. Different national legal systems have conditioned the DNA databases and so there is a great heterogeneity between countries. The criteria for an entry of a DNA profile, the criteria for a removal, the criteria for a search, etc., can lead to very distinct databases.