Volunteers and artificial intelligence used in cold cases

The use of volunteers, access to old police data and artificial intelligence can help to solve cold cases. This is important, both for surviving relatives and for society as a whole. These cases concern serious and complex crimes that have not been resolved in the past. That is what Minister Grapperhaus (Justice and Security), also on behalf of Minister Dekker (Legal Protection), wrote to the House of Representatives today.

At present, more than 1,700 cases have been classified as cold cases by the police and the Public Prosecution Service. These involve unsolved murders, manslaughter or very serious crimes punishable by 12 years' imprisonment or more. New information, insights and the application of new techniques can lead to a breakthrough in the investigation.


Police volunteers can make a valuable contribution to the cold case investigation, including the digitalisation of investigation files. Digitalisation is required in order to organise a case file according to modern insights and make it digitally searchable. This also makes it easier to establish links between different items of police data.

It also makes it possible to use volunteers with specific knowledge and skills in cold cases. The General Legal Status (Police) Decree will be adapted to enable external specialists to be deployed more quickly. These will include notaries and cyber specialists.

Artificial intelligence

The police are conducting an experiment in which artificial intelligence is used to more effectively identify which of the 1,700 cold cases might benefit from new forensic investigation. Currently, this is a manual process which takes four to six weeks per case. The aim of the experiment is to obtain a ranking of cold cases which probably contain the most promising avenues for further investigation. The first phase of the experiment had positive preliminary results. Based on the results of the entire experiment, the police will collaborate with the Public Prosecution Service to examine whether and how this technique can be further developed for application in practice.

Old police data

The Police Chief has indicated that the current retention periods for older police data specified in the Police Data Act are too short for cold case investigations. This concerns older police data that was not previously involved in the actual investigation. If this data were to be destroyed in accordance with the current Police Data Act, this might lead to the loss of relevant information which could contribute to solving a cold case. The Police Chief has decided not to destroy this data and has taken measures to restrict access to this data to that which is strictly necessary. A limited number of so-called gatekeepers have been designated; they are the only people with access to this protected police data.

Minister Grapperhaus supports this approach by the Police Chief. It was previously announced that the Police Data Act would be revised in order to strike a better balance between the importance of proper task execution and the importance of protecting privacy. At the moment, it would be preferable to accept this deficiency in compliance with the law and to settle for the steps taken by the Police Chief to restrict access to the data to that which is strictly necessary. Compliance with the letter of the law could only be achieved by means of a coarse selection method, which would also destroy data that could contribute to detection in cold cases. This would seriously impede the resolution of these cases. This is now being prevented.

Ministry responsible