Research ‘The police can learn a lot from citizen participation in missing person cases’ Written on Wednesday, November 26, 2025 In police missing person searches, citizens can be very valuable as extra eyes and ears. Whether this deployment of citizens goes well depends on several factors. These experiences could be used to make use of citizen participation in criminal investigations in other ways too. ‘If the police want to collaborate more with citizens, missing person searches provide a fitting example of how this can be approached and what the benefits may be.’ This is the view of Jerôme Lam, a researcher at the Netherlands Police Academy. Jerôme recently received his PhD from the University of Twente for his thesis with the title ‘All in Search of the Missing - Citizen Participation in Missing Person Searches’. His thesis sets out: how citizens and police collaborate; what psychological factors motivate citizens to take part in searches; why investigators may choose to involve citizens in a search; and how technology such as an app can support citizens’ search activities. Special policing ‘Missing person cases are quite an unusual form of policing’, Jerôme explains. ‘At the start you often don’t know exactly what it’s all about. When someone first goes missing, it’s possible they have had a medical emergency or been in an accident. But equally they may be confused and may have wandered off. Or they may be the victim of a crime. Depending on the situation, it could call for emergency assistance, it could be a law enforcement issue, or it could be the start of a criminal investigation.’ ‘When the police launch a missing person search, they often have limited search capacity. If citizens can supplement that capacity, that’s great, and a great opportunity for the police. If there isn’t much information, it’s also difficult to know how best to deploy police capacity. That was how it was at the start of the Anne Faber case, for instance: the police had no indication at all where she might be. At that point, members of Anne Faber’s family started their own search, on the basis of their own investigation and their own ideas.’ ❛❛ To my mind, the approach to citizen participation in missing person cases forms a sort of blueprint for how you could make use of citizens’ knowledge and expertise in criminal investigations in other ways. Risks ‘A citizen search is always effective, a colleague of mine said recently’, Jerôme continues. ‘Even if nothing is found in a certain area – that tells you there is very probably nothing there to find. In that sense it’s already contributing to an investigation.’ ‘But citizen search activities do also pose a risk. If citizen searchers trample all over a given area without proper care, there’s always a danger they may destroy traces. Or they may generate new traces. At a certain point you can’t tell anymore what traces were caused by a search team and what were original traces. It’s very important to keep track – otherwise the police won’t know who did what where.’ ‘The type of investigation also plays an important role here. Searching for a missing person in an emergency assistance situation is rather different from when there’s a suspicion of a criminal offence. In that case criminal investigation will be very important.’ Contact is crucial ‘Missing person cases are pretty complex’, Jerôme comments. ‘It’s very easy for citizens to involve themselves in them. Even if the police are searching somewhere, citizens can often also just go and start searching in that area. And there’s nothing much you can do to stop them.’ ‘That’s an important lesson we learned from the Anne Faber case. The police approach shouldn’t be to try to prevent participation. We have to try to make contact – in this case with the victim’s family – and find out what they’re doing and what support we might be able to provide. If the police can collaborate with the family, that really does have added benefit.’ ‘But if for some reason collaboration isn’t possible, you can’t just turn a blind eye. At the very least, you could ask the citizens to keep the police informed of developments. Good communication will also help prevent someone doing something without fully understanding the consequences. The police can keep the family informed about what they’re doing. Often you can’t tell citizens anything about the content of an investigation, but you can inform them about the process. In any case, the crucial thing is to make contact.’ No fixed roles Jerôme emphasises that in citizen participation the distribution of roles between police and citizens is not always fixed. My police colleagues sometimes tend to see it as: the police do this and citizens do that. But it’s not a matter of fixed roles, but of who can do what and how. What does the investigation require? Whatever the situation, the missing person’s interests come first.’ ‘In May of this year two children went missing: Jeffrey and Emma. Right from the start, the police involved various citizen parties, including the Missing Persons Coordination Platform (Coördinatie Platform Vermissing, CPV) and the Veterans’ Search Team (VST), and coordinated with them who would do what. Collaborating in this way leads to a very effective search, in which the police’s specialist skills dovetail with those of citizens.’ ‘This case is a very good example of how far citizen participation in missing person cases has come. Twelve years ago we had the case of Ruben and Julian. In the report on that case, it was noted that collaboration with citizens was not plain sailing. This time it was a similarly large case, but now the search was organised in a structured, professional, and coordinated way.’ Blueprint In his research over the years, Jerôme has come to realise that until now it is mainly only in missing person cases that extensive citizen participation works well. ‘In these cases it is really part of the process, is actively used, and is well developed. And it makes a structural contribution.’ ‘To my mind, the approach to citizen participation in missing person cases forms a sort of blueprint for how you could make use of citizens’ knowledge and expertise in criminal investigations in other ways: the whole way it is organised, in terms of procedures, deployment criteria, single point of contact, and agreements with citizen partner organisations, etc.’ ‘In the police organisation we’ve been saying for years that we should make more use of citizens’ knowledge and expertise. But when it comes down to it, this often proves quite difficult. Police officers don’t know how to go about it. Or they only think of it quite late on, as a last resort. In missing person cases, you do see this citizen participation, and the trend continues to rise. I think the police can learn a lot from how collaboration is organised in these cases.’