The Danish National ID Centre’s biometric unit is tasked with the provision of assistance to the Danish immigration authorities by strengthening their capacity to identify and verify the identities of foreign citizens through the examination of certain biometric characteristics.

Biometrics can be described as a method to identify or verify the identity of a person by examining certain biological and physiological traits and characteristics, such as, but not excluded to, fingerprints, facial features, iris and voice. The Cen-tre’s biometric unit currently only conducts facial image comparisons, but will also conduct fingerprint identification at a later stage.


Fingerprints have been used for identification purposes since the 19th century. They can be used to determine whether an asylum seeker has filed an asylum claim in another European country prior to filing an asylum claim in Denmark. Fingerprint examinations are performed by specially trained personnel and are conducted according to the ACE-V procedure, where the pattern and details of the fingerprints are compared to determine whether they come from the same person.

Facial image comparison

Facial image comparison is a process, in which, two or more facial images are compared to assess the probability of whether the images depict the same person or not. For further information see different types of facial image comparison.

The comparison of facial images is conducted by specialised case officers, who conduct the comparison based on rigidly defined workflows that have been for-mulated in accordance with internationally renowned methods and procedures.

At the Danish National ID Centre, facial images are compared using a morphological analysis, which entails a systematic description and comparison of the relevant facial features, such as the nose, eyes, ears and mouth. The ability to conduct a facial image comparison or determine whether images depict the same person or not, is dependent on a number of factors, such as the quality of the image, illumination, pose of the subject in relation to the camera, as well as the age of the depicted subject and the timeframe between when the images were taken.

To ensure the quality of the manual comparison process, each facial image com-parison case is assessed by two case officers following a “double blind procedure”, where the images are assessed independently by the two separate case officers, who are unaware of the identity of the second case officer during the comparison process. The independent findings of each case officer are compared upon the completion of the comparison process, and a shared conclusion is then formulated. Following this procedure prevents the case officers from being influenced by the opinions of the other case officer conducting a comparison in the same case, and minimises the risk of influence from a number of other external factors.

It is important to note, that the results and findings of forensic facial examinations traditionally cannot stand alone as evidence in criminal or administrative proceeding, and they should therefore only be used as a supplemental element in the assessment of a case. Results from this type of examination can thus contribute to determining the facts of a case for the authority responsible for taking a subsequent administrative decision.

Further information regarding the processing of personal data can be found here: Processing of personal data contained within documents that are subject to examination and authentication