QUANTICO, Virginia—More than 30 years ago, the Federal Bureau of Investigation launched a revolutionary computer system in a bomb shelter two floors beneath the cafeteria of its national academy. Dubbed the Violent Criminal Apprehension Program, or ViCAP, it was a database designed to help catch the nation’s most violent offenders by linking together unsolved crimes. A serial rapist wielding a favorite knife in one attack might be identified when he used the same knife elsewhere. The system was rooted in the belief that some criminals’ methods were unique enough to serve as a kind of behavioral DNA—allowing identification based on how a person acted, rather than their genetic make-up.
Equally as important was the idea that local law-enforcement agencies needed a way to better communicate with each other. Savvy killers had attacked in different jurisdictions to exploit gaping holes in police cooperation. ViCAP’s “implementation could mean the prevention of countless murders and the prompt apprehension of violent criminals,” the late Senator Arlen Specter wrote in a letter to the Justice Department endorsing the program’s creation.
In the years since ViCAP was first conceived, data-mining has grown vastly more sophisticated, and computing power has become cheaper and more readily available. Corporations can link the food you purchase, the clothes you buy, and the websites you browse. The FBI can parse your emails, cellphone records, and airline itineraries. In a world where everything is measured, data is ubiquitous—from the number of pieces of candy that a Marine hands out on patrol in Kandahar, to your heart rate as you walk up the stairs at work.