Denmark entered the Schengen cooperation on 25 March 2001.The objective of the Schengen cooperation is, among other things, to enable citizens to travel freely within the Schengen area.
As part of the Schengen cooperation, close collaboration has been established between the countries’ police forces in order to prevent international and cross-border crime, and to strengthen efforts in combating these crimes. For the purpose of this work, a special information system, Schengen Information System (SIS) has been established.