Experts: Advances leading to breakthroughs

The effort to solve decades old cold cases is paying dividends in recent years as investigators take advantage of a host of new tools, including advanced technology, public input driven by social media, time and fresh perspectives on old evidence.

“DNA solves approximately 25% of cold cases,” said cold case analyst Sarah Stein. “While that is not insignificant, other investigative tools, such as behavioral crime analysis, informational evidence gathering, and public engagement are also critically important to resolving these cases.”

In Massachusetts, advances in sonar technology led to the discovery of Judy Chartier’s car and remains in the Concord River, and more sensitive DNA technology cracked Jane Britton’s case.

“We used to have to have a solid DNA sample that had not deteriorated, had not been compromised in any way, in order to get a good profile of who this person was. That’s not the case anymore,” said

Sheryl Mccollum, director of the Cold Case Investigative Research Institute.

She said that advances in DNA technology also allow investigators to extract samples from objects like bullet shell casings and rope. Stein said that other technologies “can render a composite sketch from an unknown DNA sample,” which can then be used to jog someone’s memory.

Other technologies like drones and ground-penetrating radar, originally used in other contexts, can also be helpful for spotting weapons, bones or other objects, Mccollum added.

Interest in cold cases among the public has also led to an increase in cracked cases, the experts said.

“We are seeing people communicate like never before on social media, and law enforcement has used this to their advantage by appealing to people through social media platforms,” Stein said, citing the recent viral case of Gabby Petito, whose body was found largely due to the work of internet sleuths. “The importance of public engagement cannot be overstated.

Mccollum cited citizens’ roles in cracking the D.C. Sniper and Zodiac Killer cases. And with the ease of publishing to the internet, “anybody can put out a podcast about a cold case and try to help get witnesses to come forward,” she said. “That’s huge.”

The biggest factor in solving cold cases, she said, is time.

“If you have a child that is a witness to something, and they’re 12, and they’re scared to death, by the time they’re 40, they’re not scared anymore,” Mccollum said.