Naturally, PET has a close co-operation with other Danish police departments. Each police district designates a special contact person to PET, and the Service offers technical assistance etc. and carries out special assignments of an investigative nature for the police districts.

Furthermore, the Service prepares risk assessments to be used by the districts in connection with actual incidents or in general, e.g. when heads of state visit Denmark, demonstrations that may develop violently or possible terrorist threats. The risk assessments are usually accompanied by a number of recommendations as to which emergency measures should be initiated and, as such, constitute a part of the total planning basis of the districts.

If a PET investigation justifies charges being brought or other measures being taken as part of a criminal case, the responsibility for further investigation shall be passed on to the prosecutors of the specific police district. However, such measures do not prevent the Service from offering assistance to any further investigation.

The Danish Defence Intelligence Service, DDIS, (Forsvarets Efterretningstjeneste (FE))

PET co-operates closely and co-ordinates measures in a number of areas with the Danish Defence Intelligence Service. As mentioned above, PET’s role is to monitor and fight threats to Denmark’s national security, whereas the Danish Defence Intelligence Service’s role is to monitor threats from abroad. International developments have resulted in the threats to Denmark’s and allied nations' security being of such a nature that national threats and those from abroad are not easily separated. The co-operation is secured through contacts and co-ordination between the staff of the two services at management and desk officer level as well as in special working groups.

The co-operation includes countering terrorism, where PET and DDIS prepare joint assessments of the threat from international terrorism. The co-operation also covers the area of non-proliferation as well as activities within the technical field. Furthermore, the two services exchange staff with the aim of strengthening the knowledge of each other’s working practices and methods.