How the Police Track Ordinary Citizens

When the police chat to an innocent citizen on the street or speak to someone that they believe may be acting suspiciously they complete field interview or contact cards to document the encounter. One result of this practice is that citizens who have never broken the law are documented in police databases. This data can then be used to keep a record of their movements, habits and acquaintances.

The Post & Chronicle used freedom of information requests to access this data from the Charleston, North Charleston and Mount Pleasant Police Departments. They discovered that the Charleston Police Department’s database for field contacts has records of 35,000 people, or about a quarter of the city’s population.

The Post & Chronicle has mapped the field contacts data of the Charleston police. The Watched map shows the location of each encounter logged by the police as a white dot. The lines on the map connect the white dots of citizens who have been entered into the database more than once.

If you select a dot on the map you can isolate an individual's data on the map. For example, in the screenshot above, you can see the entries of citizen 'ID 3110'. This person has had their details taken by the police 415 times. The mapped visualization of this data gives a good idea of how the police can use this data to build up a picture of a citizen's movements and other habits.