How cold case DNA technique came to Ottawa from California — and where it's headed next

Family tree enthusiasts and the websites that cater to them are helping police solve decades-old homicides, including here in Ottawa. And the former California district attorney who helped bring the technique to the world with the prosecution of the Golden State Killer back in 2018 says it has the potential to solve many more — as long as it's managed appropriately.

Investigative genetic genealogy — the process of using DNA to find relatives of unidentified suspects and victims of crime — burst into the consciousness in eastern Ontario last year when Ontario Provincial Police used it to help identify the Nation River Lady.

She was found dead nearly 50 years ago, floating in the Nation River after being dropped from a bridge on Highway 417 between Montreal and Ottawa. She wasn't identified as Jewell Parchman Langford until decades later, and her alleged killer remains before the courts on a charge of murder.

Now, investigative genetic genealogy has been used for the first time by Ottawa police to help identify a suspect in the stabbing death of a man on the Portage Bridge back in 1996.

Twenty-nine years later, Lawrence Diehl, who is now 73, is facing a charge of second-degree murder in Christopher Smith's killing, and remains in custody as his case begins to make its way through the courts. The allegations against him have not been proven.

It's taken four years for Ottawa police to get to this point.

In 2020, as genetic genealogy started making more and more headlines in old police investigations, Ottawa police put Sgt. Chris O'Brien in charge of figuring out which cases might benefit from the new technique.

He put out a call to the rest of the homicide unit to go through dozens of cold cases and find any containing a DNA profile they know belongs to a suspect, but which didn't yield results in traditional DNA databank searches.

Sgt. Mahad Hassan suggested the Smith case and they both agreed it met the bar, O'Brien said. From there, they had to bring the 1996 investigation up to code, so to speak.

"With a lot of these old cases, it's about bringing a lot of what was done 30 years ago into the modern standard that's accepted for prosecutions in court today," O'Brien said.

"It's a long, gruelling, painstaking process to go through all that work."

To find out more about their heritage, people use companies like 23andMe, Ancestry and others to upload their DNA and trace family links through the generations.

But many of those companies don't allow law enforcement to upload DNA profiles of unidentified suspects and victims of crime to compare with their users.

GEDmatch and FamilyTreeDNA do, however — for users who have specifically opted in.