FORENSICSA New Strategy to Speed Up Cold Case Investigations

Published 19 September 2022

Solving crimes with forensic genetic genealogy is slow and complicated. A new mathematical analysis could crack cases 10 times faster.

For nearly 37 years, she was known as Buckskin Girl — a young, anonymous murder victim found outside Dayton, Ohio, wearing a deer-hide poncho. Then, in April 2018, police announced that the mystery of her identity had been solved. Her name was Marcia L. King, and she had been identified by linking a snippet of her DNA to one of her cousins.

It was one of the first high-profile cases in which this investigative method had been used to identify an unclaimed body. Two weeks after King’s name was revealed, police in California announced that they’d used similar techniques to track down the Golden State Killer. Suddenly, the combination of genetic sampling, genealogical research, and old-fashioned gumshoeing was hailed as a revolutionary breakthrough that would crack hundreds of cold cases.

Since then, forensic genetic genealogy has cleared more than 400 cases in the U.S. Yet this detective work is complex and time-consuming. While King was IDed after just a few hours of sleuthing, most cases take much longer. On average, they take over a yearopen in new window to solve successfully. Many are left unfinished: Law enforcement agencies may run out of funding before a person can be identified and investigators may give up if they hit too many dead ends.

A more systematic approach would help, says Lawrence Wein, a professor of operations, information, and technology at Stanford Graduate School of Business. With Mine Su Ertürkopen in new window, PhD ’22, he has unveiled a method for solving cold cases with more speed and success. In a new paper in the Journal of Forensic Sciences, they present the first detailed mathematical analysis of the forensic genetic genealogy process and outline a way for investigators to optimize searches for unknown victims or criminal suspects.

To develop their search method, Wein and Ertürk teamed up with the DNA Doe Projectopen in new window, a California nonprofit that has solved more than 65 cases of unidentified remains, including the King case. It provided the researchers with data from 17 cases, including 8 that were unsolved at the time. “That’s quite similar to the historical average of cases they’ve solved,” Wein says. “So there’s no reason to suspect that these cases are much harder or much easier than randomly selected cases.”