Since 1998, the Dutch police have been using Automatic Number Plate Recognition (ANPR). ANPR means that a camera reads license plates of motor vehicles, the system compares the license plate read in with a reference file: a list of license plates with 'something' (Streefkerk, 2016). This concerns, for example, a vehicle that has been identified as stolen or is being searched for in connection with a criminal investigation. If a vehicle appears in a reference file, this gives a 'hit', after which the police can decide on a certain action ('follow-up'). A hit from a fixed ANPR camera can be read out by police officers on their mobile phones. Hits can also come in directly via mobile ANPR equipment in a police vehicle. In the early days of ANPR in the Netherlands, only mobile cameras were used, and since 2004 it has also been possible to use fixed cameras. The camera density has increased considerably in recent years, as has the number of police officers using ANPR (hereafter: end users). In the period from May 2017 to March 2018, the number of end users increased from 4,000 to over 8,000. The Cabinet sees ANPR as an important tool for police work. This is evident from the coalition agreement on 'Freedom and Responsibility' (coalition agreement, 2010, p. 42). The coalition agreement states that vehicle recognition contributes to the 'prevention and simplification of the investigation and prosecution of criminal offences and to the enforcement of tax obligations'. This coalition agreement was the reason to expand ANPR's efforts. Despite the importance attributed to ANPR, little is known about the effects of ANPR in police work. This study provides insight into the use of ANPR in practice. In order to know how ANPR use can be improved, it was examined how this use relates to the intended objectives. This study, commissioned by the National Coordination Team ANPR (LCTA), aims to contribute to the optimisation of the use of ANPR. This research deals with the effects of ANPR in police work, in terms of police activities (what do policemen do?) and the police results that follow, such as an arrest or an official report. The social effects that these results in turn lead to, such as 'a safer society', are beyond the scope of this research. Nor does the study deal with the question of whether ANPR leads to more efficient police work. Furthermore, this report deals to a limited extent with the technical side of ANPR and is mainly focused on the views, experiences and the way in which ANPR is used by end-users. End-users' in this context means that these users of hits can read out via built-in mobile devices or via the fixed ANPR camera on their smartphone (fixed camera) or via built-in mobile devices, but that they are not authorized to make reference lists. The further development of ANPR may take into account the findings of this investigation.