When a case is cold, investigators must adapt.
About 30 police officers from the RCMP and other agencies hoping to thaw cold cases, recently picked up new skills at the Canadian Police College.
The Unsolved and Historical Death Investigation Course, the first of its kind at the college, covered topics from investigative and forensic anthropology to DNA science and interviewing methods.
"The hot case and the cold case are different beasts," says RCMP Sgt. Ghislain Ringuette, who works in investigating training at the college, adding the course provides standardized methodology and the latest in cold-case investigative strategies.
Classes covered strategies such as geographic profiling — using maps and location analysis to focus a search area — and cognitive interviewing — a non-accusatory style focusing on memory recall and historic events. Officers learned how social media and soliciting public tips can help develop leads during an investigation.
One lecture covered recent innovations in DNA science and technology allowing police to take new paths with previously untestable DNA evidence.
Another session shed light on investigative genetic genealogy, which uses crime scene DNA, online databases and genealogy research to develop evidence.
Experts from U.S. agencies who use the technique explained that investigators link DNA to distant relatives and build family trees using public records and newspaper archives, filling gaps to find a suspect name.
The technique led American investigators to Joseph DeAngelo, who was dubbed the Golden State Killer and allegedly committed scores of burglaries, sexual assaults and murders in the 1970s and 1980s.
Since DeAngelo's 2018 arrest and charges, dozens of historic American homicides and sexual assaults have been solved using the technique. In Canada, the Vancouver Police Department and Canadian Border Services Agency have used the approach.
Cpl. Mike Burns of the Yukon RCMP Historical Case Unit, says the method opens up a "brand new window for investigations."
"This could help with unidentified remains cases where there can be DNA but few investigative leads," says Burns, who's been with the RCMP for 32 years.
The National Centre for Missing Persons and Unidentified Remains lists nearly 300 cases of unidentified remains dating back to the mid-1960s.
Experts stressed the new technology doesn't replace traditional door-knocking and interviewing.
"You still need the footwork to get the job done," Burns says. "These historic cases are marathons, not a sprint."
While it's hard to determine how many homicides become cold cases, Statistics Canada reports that on average, 70 per cent are considered solved each year.
While the course focuses on investigative skills, it doesn't ignore the more personal aspects.
"A case is more than the paper, more than pictures and more than files," says Ringuette.
RCMP Cpl. Grace Wood says a presentation from a sexual assault victim and the police officer who solved the case a decade later reaffirms the value of historic case work.
"It's important we work to serve the victim and their families and bring justice and closure," says Wood, who works in serious crimes in British Columbia.
Maryanne Pearce, RCMP advisor on reconciliation and murdered and missing Indigenous women and girls, discussed nuances of communicating with victim families and witnesses in a culturally informed manner.
Pearce explained the importance of keeping family up to date on investigations and the benefits of things such as a neutral meeting place when interviewing some witnesses and talking with community elders.
"Officers work in Indigenous communities and while one presentation doesn't revolutionize the world, we wanted to show some approaches," says Ringuette, adding it's important information as Indigenous people can be overrepresented as victims of crime.