Day 6

This journalist built an algorithm that can spot serial killers police missed

In 2010, former data journalist Thomas Hargrove developed an algorithm that he hoped could help hunt serial killers by spotting patterns police can't see. He's already put it to use in Cleveland, Ohio and Gary, Indiana, and now, he's making it available for free to anyone who wants to use it, as part of the Murder Accountability Project (MAP), an effort to crowd-source the hunt for killers.
The Murder Accountability Project used data from the Green River Killer to train its algorithm to discover patterns in unsolved murders. (Elaine Thompson, AP / Murder Accountability Project)
Listen9:06

A non-profit group called the Murder Accountability Project, or MAP, is hoping that their algorithm can help solve the 5,000 murders that go unsolved every year in the United States.

The project, led by former data journalist Tom Hargrove, uses publicly available statistics provided to the FBI, as well as data from police forces obtained via freedom of information requests, to try to find patterns that might indicate if any of the murders are connected.

As he tells Day 6 host Brent Bambury, Hargrove first had the idea to create the algorithm while working on a story about rape cases. During his research, he came across a tool that would become the crucial to the Murder Accountability Project: the FBI's Uniform Crime Report.

Could we teach a computer to connect those cases that had a common killer?- Tom Hargrove, the Murder Accountability Project

"I opened the file and saw row after row of murders. The demographic information of the victim, their age, sex, race, the method of their killing, and similar information about the offender, if the offender had been arrested," explains Hargrove. "I don't know where these ideas come from, but the first thing that came to mind was, 'could we teach a computer to connect those cases that had a common killer?'"

To teach and test the algorithm to identify patterns, Hargrove and the other researchers used data from the murders committed by Gary Ridgway, also known as the Green River killer. In 2003, Ridgway was convicted of killing 48 women in the Seattle area.

MAP now has records on more than 700,000 murders that have been committed since 1980. 



While his organization does work with police forces, Hargrove also gets help from the public. He says that it's a way to crowdsource murder.

"There are millions of Americans who have an interest in this, and these are public records, after all. Why not create a fairly easy-to-use system so that people can look at their community, or any community that interests them, and test whether there might be unusual activity?" 

This week, in a partnership with Cleveland's Plain Dealer, the Murder Accountability Prjoect revealed a previously unseen pattern in a string of murders, which some former police officers now say could be the work of a serial killer. 

Hargrove says that the Murder Accountability Project would be happy to help with investigations into Canada's missing and murdered aboriginal women, though data from those investigations are not publicly available.