With regard to the tables and figures presented in the PKS, it must be pointed out that the informative value of the PKS is limited by the fact that some of the crimes committed are not known to the police. The extent of this dark field depends on the type of offense and changes, for example, depending on the intensity of the fight against crime or the willingness of the population to report crimes. It is therefore not possible to assume a fixed relationship between committed and statistically recorded crimes.
MIK NRW / Jochen Tack
Police crime statistics