Missing Persons Investigation

Missing persons investigations are the best way to find out what happened to a person who is missing. All reports of missing people sit within a continuum of risk from those who are likely to be safe through to those at significant risk of harm.


Despite this diversity, the police response to missing person cases is often similar to that deployed for homicide enquiries. These three case reconstructions begin to deconstruct this response.

Human Sources

The search and identification of missing persons, particularly in contexts such as migration, conflict/post-conflict, mass disaster or organised crime is not a simple task. It requires a holistic approach, not least in terms of addressing status and mobility (the two key elements that determine the trajectory of an investigation).

A number of human sources can help with this. These may include interviews with relatives, neighbours, friends, acquaintances and colleagues; door to door enquiries; tracing of mobile phones and other electronic devices; checking of police records including criminal, immigration or border control interactions; analysing CCTV footage; and searching the Internet. This information should be analysed and systematically recorded, centralized and consolidated for comparison with unidentified bodies.

This collection and analysis will also provide the opportunity to reconstruct a medical or psychological profile of a missing person, and their social history/lifestyle. This includes information such as their professional, academic and political associations; family members and other relationships; lifestyle habits, nicknames or political aliases; social, legal or other actions by the individual or by their relatives and others (habeas corpus, petitions on disappearances, paid press releases etc); and their movements over time.

In some cases, it will be necessary to enlist the support of people who claim to have psychic or extrasensory powers. These should be engaged with care as they can often put pressures on searches to concentrate on certain areas.

Database Searches

Missing persons investigations often involve determining the fate and whereabouts of missing individuals with a degree of certainty or confidence. This involves formulating a hypothesis – free of bias or presumptions – related to their disappearance, and then reconstructing the events since that time. It may include identifying the person’s likely state or condition and assessing their risk of harm.

Database searches are one of the most important aspects of a missing persons investigation. For example, if the missing person was known to change their identity in order to avoid capture by criminals, it would be useful to know if they had access to websites or books that explain how to do so. Social media information or bank account details may also give clues as to their location, particularly in cases involving trafficking or slavery.

The ICMP’s database, NamUs, is used by law enforcement professionals, missing persons clearinghouses and members of the public to search for potential matches with missing and unidentified individuals. NamUs can be searched by name or by state.

The use of the Combined DNA Index System, or CODIS, is another tool available for investigating missing persons cases. This forensic technology allows agencies to compare the DNA profiles of convicted criminals and missing people, providing clues as to their whereabouts. This type of matching is often useful in identifying serial violent criminals and other people who are known to commit serious crimes.

Forensic Collection

Missing persons investigations are among the most complex police cases that investigators are confronted with. They are a unique type of inquiry where the investigation may require the gathering and analysis of sensitive personal data, especially in a case involving slavery or trafficking, or where a missing person has been reported as part of a larger organized crime syndicate.

Responding to reports of missing persons is a high-demand on police resources and it is often a key focus for police organisations. Despite the diversity of reasons for someone to go missing and whether it is an intentional or unintentional absence there are significant similarities in the investigative approach deployed by police officers (see for example Shalev et al 2009 and Gibb and Woolnough 2007).

These case reconstructions start to reveal something about the ‘process structure’ of a missing persons enquiry. Echoing work on homicide investigations, the case reconstructions help us to see that despite the many variations in the situations that people find themselves in (intentional or not) a similar pattern of police organisational actions are enacted.

Forensic collection is a powerful tool for legal professionals, particularly in missing persons investigations where it empowers them to look beyond the words on the page and unearth deleted, hidden or encrypted data. Unlike typical e-discovery collections, which are conducted using logical collection technology, forensic collection is performed on the physical hard drive of a computer or device – this can be an important step in ensuring that responsive data is properly collected and preserved for processing in a litigation matter, or to assist law firms with meeting their obligations to uphold the duty to preserve electronic discovery for criminal matters or critical internal investigations.


Missing persons investigations are often highly sensitive and are a key area of police activity. They also have the potential to generate significant public interest over a prolonged period. As such it is important to manage the media carefully in order to avoid any potential interference with the investigation.

A full picture of the missing person should be developed as soon as practicable. This should involve building a comprehensive understanding of the individual including their lifestyle, habits and hobbies. This should contribute to the risk assessment and help identify possible reasons (or hypotheses) for their disappearance. It is the responsibility of the FLO to develop this and ensure that it remains relevant throughout the investigation.

It is also the responsibility of supervisors to make contact with relevant social networks and mobile phone providers to establish any live-time communications data which may be available (see Passive data generators). In some cases it may be appropriate to request the assistance of these organisations in the conduct of searches of the home address or last known location. This should be considered on a case by case basis and be proportionate to the circumstances of the disappearance.

Whenever possible sightings should be evaluated to determine their relevance to the investigation and a means of prioritising them should be established. These evaluations should be recorded.