In an investigation into the nation’s 50 largest police departments, The Post and Courier of Charleston, South Carolina found that the personal information of millions of innocent Americans is being stockpiled in police databases around the country.

The information is being compiled through field interviews, where police officers take notes from routine stops or conversations they have while in the field. This method is nothing new, but the databases are: Previously, field interview notes would be discarded over time. The digital age allows the information to be stored indefinitely on internal servers. This can help document a person’s habits over time, create opportunities for police misconduct, and color police perceptions of citizens before they ever commit a crime. 

The investigation is paired with an interactive graphic illustrating how police records can trace a person’s movements, as well as tools for readers to request police records in their own state.