§ 42 DSG NRW
Distinction between different categories of data subjects
(1)The controller shall, in the processing of personal data, distinguish as far as possible between different categories of data subjects. This shall concern in particular the following categories:
(2)1. persons with respect to whom there are reasonable grounds for believing that they have committed a criminal offence,
(3)2. persons with respect to whom there are reasonable grounds for believing that they will commit a criminal offence in the near future,
(4)3. convicted offenders,
(5)4. victims of a criminal offence or persons with respect to whom certain facts indicate that they could be a victim of a criminal offence, and
(6)5. other persons such as in particular witnesses, informants or persons who are in contact or association with the persons referred to in numbers 1 to 4.