âI wonder if we could teach a computer to spot serial killers in data,â Thomas Hargrove thought as he parsed the FBIâs annual homicide reports. The retired news reporter would soon answer his own question. He created an algorithm that, in his words, âcan identify serial killingsâand does.â
In The Dewey Decimal System of Death, a new film from FreeThink Media, Hargrove explains how âthe real world is following a rather simple mathematical formula, and itâs that way with murder.â
The numbers are startling. According to Hargrove, every year, there are at least 220,000 unsolved murders in the United States. Of those murders, an estimated 2,000 are the work of serial killers. Many of these cases are not ultimately reported to the Justice Department by municipal police departments; Hargrove has assiduously obtained the data himself. His Murder Accountability Project is now the largest archive of murders in America, with 27,00 more cases than appear in FBI records.
Hargrove has put the database to work with an algorithm that solves an informatics problem called âlinkage blindness.â In the U.S. justice system, Hargrove explains, âthe only way a murder is linked to a common offender is if the two investigators get together by the water cooler and talk about their cases and discover commonalities.â Hargroveâs algorithm is able to identify clusters of unsolved murders which are related by the method, location, and time of the murder, as well as the victimâs gender.
Most recently, Hargrove utilized his software to discover and alert the police department in Gary, Indiana of 15 unsolved strangulations in the area. âIt was absolute radio silence,â he says in the film. âThey would not talk about the possibility that there was a serial killer active.â After Hargrove was rebuffed, seven more women were killed. He says it was âthe most frustrating experience of my professional life.â