AI detective analyses police data to learn how to crack cases
A system called VALCRI should do the laborious parts of a crime analyst’s job in seconds, while also suggesting new lines of enquiry and possible motives
MOVE over, Sherlock. UK police are trialling a computer system that can piece together what might have happened at a crime scene. The idea is that the system, called VALCRI, will be able to do the laborious parts of a crime analyst’s job in seconds, freeing them to focus on the case, while also provoking new lines of enquiry and possible narratives that may have been missed.
“Everyone thinks policing is about connecting the dots, but that’s the easy bit,” says William Wong, who leads the project at Middlesex University London. “The hard part is working out which dots need to be connected.”
VALCRI’s main job is to help generate plausible ideas about how, when and why a crime was committed as well as who did it. It scans millions of police records, interviews, pictures, videos and more, to identify connections that it thinks are relevant. All of this is then presented on two large touchscreens for a crime analyst to interact with.
The system might spot that shell casings were found at several recent crime scenes including the one the police are focusing on now, for example. “An analyst can then say whether this is relevant or not and VALCRI will adjust the results,” says Neesha Kodagoda, also at Middlesex. Thanks to machine learning, the system improves its searches on the basis of such interactions with analysts, who can raise or lower the importance of different sets of criteria with a swipe.
When an unsolved crime lands on an analyst’s desk, one of the first things they have to do is search police databases for incidents that could be related based on their location, time or modus operandi, and collect details of all of the people involved. “An experienced analyst needs 73 individual searches to gather all of this information, before manually putting it into an easily digestible form,” says Kodagoda. “VALCRI can do this with a single click.”
This is no mean feat. A lot of the information recorded in police reports is in side notes and descriptions, but the algorithms powering VALCRI can understand what is written – at a basic level.
For example, interviews with people at three different crime scenes may describe an untidy person nearby. One person might have used the word “scruffy”, another “dishevelled” and the third “messy”. A human would have no trouble considering that all three might be describing the same person.
