From an interesting article by Sara Jabakhanji published in the VBC News web site:

Experts in genetics and criminology say this is an "exciting time" for DNA mining technology and its potential impact in helping solve cold cases — after police identified and charged a man in the deaths of two women in Toronto dating back nearly four decades.

Ontario Provincial Police arrested Joseph George Sutherland, 61, in northern Ontario on Nov. 24. Sutherland was brought to Toronto to face two counts of first-degree murder for the deaths of Susan Tice and Erin Gilmour in 1983, both of whom were sexually assaulted and stabbed to death in their beds, four months apart.

In a news conference Monday, Toronto police said the findings would not have been possible without the help of investigative genetic genealogy (IGG) to identify and trace back the family tree of the accused.

"It's a very, very exciting time because if we can essentially resolve even a small percentage more of our missing persons or unidentified human remains cases, that's really incredible," said Nicole Novroski, an assistant professor of forensic genetics at the University of Toronto.

"The technology itself is incredibly useful and incredibly powerful within this investigative arena," she told CBC Toronto.

But Novroski also said it's important that the database collected is done so with public consent. The process involves cross-referencing DNA found at crime scenes with samples voluntarily submitted to services such as 23andMe or Ancestry.ca and then uploaded to open-source databases like GEDmatch, a site that compares DNA data files from various testing companies.

"The number one thing to remember is that everybody who is in the database should be providing their consent to be in the database, to be searched against or to be searched for in order for this to be kind of a viable technology that people are comfortable using."

The full article is much longer and provides numerous details. You can read it at: https://tinyurl.com/2s4fwxss.